John C. Slater

John C. Slater

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John Clarke Slater was a noted American physicist
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...

 who made major contributions to the theory of the electronic structure of atoms, molecules and solids. This work is of ongoing importance in chemistry, as well as in many areas of physics. He also made major contributions to microwave electronics. He received a B.S. from the University of Rochester
University of Rochester
The University of Rochester is a private, nonsectarian, research university in Rochester, New York, United States. The university grants undergraduate and graduate degrees, including doctoral and professional degrees. The university has six schools and various interdisciplinary programs.The...

 in 1920 and a Ph.D. in Physics from Harvard
Harvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...

 in 1923, then did post-doctoral work at the universities of Cambridge
University of Cambridge
The University of Cambridge is a public research university located in Cambridge, United Kingdom. It is the second-oldest university in both the United Kingdom and the English-speaking world , and the seventh-oldest globally...

 (briefly) and Copenhagen
University of Copenhagen
The University of Copenhagen is the oldest and largest university and research institution in Denmark. Founded in 1479, it has more than 37,000 students, the majority of whom are female , and more than 7,000 employees. The university has several campuses located in and around Copenhagen, with the...

. On his return to the U.S. he joined the Physics Department at Harvard.

In 1930, Karl Compton, the President of MIT, appointed Slater as Chairman of the MIT Department of Physics. He recast the undergraduate physics curriculum, wrote 14 books between 1933 and 1968, and built a department of major international prestige. During World War II, his work on microwave transmission, done partly at the Bell Laboratories and in association with the MIT Radiation Laboratory
Radiation Laboratory
The Radiation Laboratory, commonly called the Rad Lab, was located at the Massachusetts Institute of Technology in Cambridge, Massachusetts and functioned from October 1940 until December 31, 1945...

, was of major importance in the development of radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

.

In 1950, Slater founded the Solid State and Molecular Theory Group (SSMTG) within the Physics Department. The following year, he resigned the chairmanship of the department and spent a year at the Brookhaven National Laboratory of the Atomic Energy Commission. He was appointed Institute Professor of Physics and continued to direct work in the SSMTG until he retired from MIT in 1965, at the mandatory retirement age of 65.

He then joined the Quantum Theory Project of the University of Florida as Research Professor, where the retirement age allowed him to work for another five years. The SSMTG has been regarded as the precursor of the MIT Center for Materials Science and Engineering (CMSE). His scientific autobiography and three interviews present his views on research, education and the role of science in society.

In 1926, he had married Helen Frankenfeld. Their three children (Louise Chapin, John Frederick, and Clarke Rothwell) all followed academic careers. John was divorced and in 1954 he married Dr. Rose Mooney, a physicist and crystallographer, who moved to Florida with him in 1965.

In 1964, John Slater and his then ninety-two-year-old father, who had headed the Department of English at the University of Rochester many years earlier, were awarded honorary degrees by that university. John Slater's name is part of the terms Bohr-Kramers-Slater theory
BKS theory
The Bohr-Kramers-Slater theory was perhaps the final attempt at understanding the interaction of matter and electromagnetic radiation on the basis of the so-called Old quantum theory, in which quantum phenomena are treated by imposing quantum restrictions on classically describable behaviour...

, Slater determinant
Slater determinant
In quantum mechanics, a Slater determinant is an expression that describes the wavefunction of a multi-fermionic system that satisfies anti-symmetry requirements and consequently the Pauli exclusion principle by changing sign upon exchange of fermions . It is named for its discoverer, John C...

 and Slater orbital.

John Slater died in Sanibel Island, Florida in 1976.

Early education


Slater's father, born in Virginia, who had been an undergraduate at Harvard, became head of the English Department at the University of Rochester, which would also be Slater's undergraduate alma mater. Slater's youthful interests were with things mechanical, chemical, and electrical. A family helper, a college girl, finally put a name (then little-known as a subject) to his set of interests: physics. When Slater entered the University of Rochester in 1917 he took physics courses and as a senior assisted in the physics laboratory and did his first independent research for a special honors thesis, a measurement of the dependence on pressure of the intensities of the Balmer lines of hydrogen.

He was accepted into Harvard graduate school, with the choice of a fellowship or assistantship. He chose the assistantship, during which he worked for Percy W. Bridgeman. He followed Bridgeman's courses in fundamental physics and was introduced into the then new quantum physics with the courses of E. C. Kemble. He completed the work for the Ph.D. in three years by publishing his (1924) paper Compressibility of the Alkali Halides, which embodied the thesis work he had done under Bridgeman. However his heart was in theory and his first publication was not his doctor's thesis, but a note (1924) to Nature on Radiation and Atoms.

After receiving his Ph.D., Slater held a Hamard Sheldon Fellowship for study in Europe. He spent a period in Cambridge, England, before going to Copenhagen. There he explained to Bohr and Kramers his original idea that classical radiation fields guided light quanta, a sort of forerunner of the duality principle. The result of Slater's conversations was the celebrated paper (1924) on "The Quantum Theory of Radiation" published in the Philosophical Magazine
Philosophical Magazine
The Philosophical Magazine is one of the oldest scientific journals published in English. Initiated by Alexander Tilloch in 1798, in 1822 Richard Taylor became joint editor and it has been published continuously by Taylor & Francis ever since; it was the journal of choice for such luminaries as...

. Known as the BKS
BKS theory
The Bohr-Kramers-Slater theory was perhaps the final attempt at understanding the interaction of matter and electromagnetic radiation on the basis of the so-called Old quantum theory, in which quantum phenomena are treated by imposing quantum restrictions on classically describable behaviour...

 paper for its authors, this paper resulted in Slater suddenly becaming an internationally known name. Interest in this "old-quantum-theory" paper subsided with the arrival of full quantum mechanics, but Philp M. Morse's biography states that "in recent years it has been recognized that the correct ideas in the article are those of Slater."

On returning to America, Slater joined the Harvard Physics Department.

Chairing the Department of Physics at MIT


When he became President of MIT, Karl Compton
Karl Taylor Compton
Karl Taylor Compton was a prominent American physicist and president of the Massachusetts Institute of Technology from 1930 to 1948.- The early years :...

 "courted" Slater to chair the Physics Department. "Administration (of the Department) took up a good deal of time, more time than he (Slater) would have preferred. John was a good chairman." The following items from the successive issues of the annual MIT President's Report trace the growth and visibility of the Department under Slater's leadership, before World War II, and the ability of the Department to contribute to defence during the war. The first two quotations are from chapters written by Compton in the successive Reports. The other quotations come from the sections about the department, that Slater wrote. These include statements affecting policies in physics education and research at large, and show his deep commitment to both.
  • 1930: "The selection of Dr. John C. Slater as head of the (Physics) Department will strengthen ... undergraduate and graduate work ... the limitation of space has retarded the development of graduate work ... the total number of undergraduates being 53 and ... graduate students 16." (p. 21)
  • 1931: "This has been the first year of the Department in charge of its new Head, Professor John C. Slater ... the subjects actively (researched include) Spectroscopy
    Spectroscopy
    Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative...

    , Applied Optics, Discharge of Electricity in Gases, Magneto-Optical Phenomena
    Magneto-optic effect
    A magneto-optic effect is any one of a number of phenomena in which an electromagnetic wave propagates through a medium that has been altered by the presence of a quasistatic magnetic field...

    , Studies of Dielectric
    Dielectric
    A dielectric is an electrical insulator that can be polarized by an applied electric field. When a dielectric is placed in an electric field, electric charges do not flow through the material, as in a conductor, but only slightly shift from their average equilibrium positions causing dielectric...

    s, and various aspects of modern and classical theoretical physics." (p. 42)
  • 1932: In the list of papers published by MIT faculty, items 293 to 340 are listed under Department of Physics. (p. 206-208)
  • 1933: "The George Eastman Research Laboratory, into which the Department moved at the beginning of the year, provides for the first time a suitable home for research in Physics at the Institute". Slater states that outside recognition is shown by holders of six National, an International, and a Rockefeller Research Fellowship choosing to come to the Department. Slater describes the dedication of the Laboratory, the hosting of meetings of the International Astronomical Union, the American Physical Society, and a Spectroscopic conference, and ends: "In general the year has been one of settling down to work under satisfactory conditions, after the more difficult transition of the preceding year." (p. 96-98)
  • 1934: "A number of advances in undergraduate teaching have been made or planned." Among the "most conspicuous events" in the department, "we acted as host" to meetings of the National Academy of Sciences, the American Association for the Advancement of Science, the American Physical Society, and a national Spectroscopic Conference, where "the main topic was relation to biology and related fields." Advances in research have been "taking advantage of the unusual facilities" in the Department, and include the work of Warren on structure of liquids, Mueller on dielectric properties, Stockbarger on crystal physics, Harrison
    George R. Harrison
    George Russell Harrison was an American physicist.Harrison became Professor of Experimental Physics at the Massachusetts Institute of Technology in 1930, and was appointed the school's Dean of Science in 1942; he also headed MIT's Spectroscopy Laboratory...

     on automating spectroscopic measurement, Wulff on hyperfine structure, Boyce on spectra of nebulae, Van der Graaff
    Robert J. Van de Graaff
    Robert Jemison Van de Graaff, was an American physicist, noted for his design and construction of high voltage generators, who taught at Princeton University and MIT.-Biography:...

     on high voltage and nuclear research, and Stratton
    Julius Adams Stratton
    Julius Adams Stratton was a U.S. electrical engineer and university administrator. He attended the University of Washington for one year, where he was admitted to the Zeta Psi fraternity, then transferred to the Massachusetts Institute of Technology , from which he graduated with a bachelor's...

     and Morse
    Philip M. Morse
    Philip McCord Morse , was an American physicist, administrator and pioneer of operations research in World War II. He is considered to be the father of operations research in the U.S.- Biography :Morse graduated from the Case School of Applied Science in 1926 with a B.S. in physics. He earned his...

     on ellipsoidal wave functions. (p. 104-106)
  • 1935: Considerable attention is given to major improvements in undergraduate teaching. The extensive comments on research mention the arrival of Robley Evans and his work on a field new to the department—radioactivity, with special attention to nuclear medicine
    Nuclear medicine
    In nuclear medicine procedures, elemental radionuclides are combined with other elements to form chemical compounds, or else combined with existing pharmaceutical compounds, to form radiopharmaceuticals. These radiopharmaceuticals, once administered to the patient, can localize to specific organs...

    . (p. 102-103)
  • 1936: "The most important development of the year in the Department has been the growing recognition of the significance of applied physics. There has been a tendency in the past among physicists to take interest only in the direct line of development of their science, and to neglect its applications." Slater develops this theme at length, and describes actions within the undergraduate, graduate and faculty work of the Department and at the national level to develop Applied Physics
    Applied physics
    Applied physics is a general term for physics which is intended for a particular technological or practical use.It is usually considered as a bridge or a connection between "pure" physics and engineering....

    . The description of the flourishing basic research refers to ten different areas, including the upsurge in work on radioactivity. (p. 131-134).
  • 1937 to 1941: These continue in the same vein. But world affairs begin to impact. The 1941 report ends: "The X-ray branch had as a guest Professor Rose C. L. Mooney of Newcomb College, who was prevented by the war from carrying on research in Europe under a Guggenheim Fellowship ... As the year ends, the National Defense effort is beginning to claim the services of a number of staff members. Presumably the coming year will see a large intensification of the effort, though it is hoped that the interference with the regular research and teaching will not be too severe." (p. 129)
  • 1942: This told a very different story. The defense effort had begun to "involve a considerable number of personnel, as well as a good deal of administrative work. With the opening of the Radiation Laboratory of the National Defense Research Committee at the Institute, a number of members of the Department's staff have become associated with that laboratory" followed by a list of over 10 senior faculty who had, and several more gone to other defense projects. (p. 110-111)
  • 1943 to 1945: Slater took leave of absence as Chair, to work on topics of importance in radar.
  • 1946: Slater had returned as Chair. He starts his report: "The year of reconversion from war to peace has been one of the very greatest activity. ... Physics during the war achieved an importance which has probably never before been attained by any other science. The Institute, as the leading technical institution of the country and probably the world, should properly have a physics department unequaled anywhere." He lists plans to meet this objective, that proliferate his administrative responsibilities. (p. 133-143)
Setting up interdepartmental laboratories, by restructuring existing laboratories using, as a model, the conversion of the Radiation Laboratory
Radiation Laboratory
The Radiation Laboratory, commonly called the Rad Lab, was located at the Massachusetts Institute of Technology in Cambridge, Massachusetts and functioned from October 1940 until December 31, 1945...

 into the Research Laboratory of Electronics
Research Laboratory of Electronics at MIT
The Research Laboratory of Electronics at the Massachusetts Institute of Technology was founded in 1946 as the successor to the famed MIT Radiation Laboratory of World War II....

 (RLE) by Julius Stratton and Albert Hill
Albert G. Hill
Professor Albert G. Hill, a physicist, was a key leader in the development of radar in WWII, director of the MIT Lincoln Laboratory development of the electronic Distant Early Warning and SAGE continental air defense systems, and first chairman of The Charles Stark Draper Laboratory. He died in...

.
Financing student assistantships and helping shape the role of government financing on an unprecedented scale.
Overseeing Robley Evans' Radioactivity Center (containing a cyclotron) and Van de Graaff's High Voltage Laboratory.
Recruiting physicists familiar with the Manhattan project
Manhattan Project
The Manhattan Project was a research and development program, led by the United States with participation from the United Kingdom and Canada, that produced the first atomic bomb during World War II. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the US Army...

 to build the Laboratory for Nuclear Science and Engineering. This was directed by Jerrold Zacharias. Its first members included Bruno Rossi
Bruno Rossi
Bruno Benedetto Rossi was a leading Italian-American experimental physicist. He made major contributions to cosmic ray and particle physics from 1930 through the 1950s, and pioneered X-ray astronomy and space plasma physics in the 1960s.-Biography:Rossi was born in Venice, Italy...

 and Victor Weisskopf.
Setting up the Acoustics Laboratory, directed by Richard Bolt
Richard Bolt
Richard Henry Bolt Ph.D., better known as Richard Bolt or Dick Bolt, was a physics professor at MIT with an interest in acoustics...

, and the Spectroscopy Laboratory directed by the chemist Richard Lord
Richard c. lord
Professor Richard Collins Lord was born in Louisville, Kentucky. He received the Ph.D. degree in physical chemistry from Johns Hopkins University in 1936...

.
  • 1947: With the hiring of staff and building of laboratories well in hand, Slater begins: "The year in the Physics Department, as in the rest of the Institute, was one of starting the large-scale teaching of returned veterans and other students whose academic careers had been interrupted by the war." He goes on to discuss the needs of students, in the entire Institute, for Physics courses and laboratories, with particular mention of the upsurge in electronics and nuclear science, and he reports briefly on the developments following from his previous report. (p. 139-141)
  • 1948: Slater begins "The current year is the first since the war in which the department has approached normal operation. No new major projects or changes of policy have been introduced." But the department that he has built is vastly different from what it was when he started. Sixteen master's degrees and 47 doctor's degrees were granted. Twenty-five Ph.D. recipients got academic appointments in MIT and other universities. Research flourished, and many scientists visited from European universities and elsewhere in the U.S. (p. 141-143)
  • 1949: The new styled "normalcy" continued. "The approach to a steady postwar state continued with few unusual occurrences." The graduate curriculum has been revised and cryogenics enhanced. The continued growth of staff, research grants, industrial contacts and volume of publication are treated as matters of continuity, recognizing at the end, that: "The administrative load of the department has grown so much (it became) wise to appoint an executive officer". Nathaniel Frank, who had worked with John Slater for nearly two decades accepted the post. (p. 149-153)
  • 1950: The future of the Department had been set. There were "few unexpected changes". And with the continued growth, "almost every research project in the Department has concerned itself with undergraduate research". (p. 189-191)
  • 1951: Jay Stratton writes "Professor John C. Slater resigned as Head of the Department of Physics and has been appointed Harry B. Higgins Professor of the Solid State, the first appointment which will carry the title Institute Professor. Professor Slater has been granted a leave of absence for the coming year to carry on research at Brookhaven National Laboratory." (p. 30)


Throughout his Chairmanship, Slater taught, wrote books, produced ideas of major scientific importance, and interacted with colleagues throughout the local, national and international scientific communities. At the personal level, Morse states: "Through most of (the 1930s) he looked more like an undergraduate than a department head ... he could render his guests weak with laughter simply by counting ... in Danish." Much later, S.B. Trickey wrote "While I got to know him reasonably well, I was never able to call J.C. Slater by his given name. His seeming aloofness turned out more to be shyness."

Atoms, molecules and solids: research preceding World War II


Returning in time to 1920, Slater had gone to Harvard to work for a Ph.D. with Percy Bridgman
Percy Williams Bridgman
Percy Williams Bridgman was an American physicist who won the 1946 Nobel Prize in Physics for his work on the physics of high pressures. He also wrote extensively on the scientific method and on other aspects of the philosophy of science.- Biography :Bridgman entered Harvard University in 1900,...

, who studied the behaviour of substances under very high pressures. Slater measured the compressibility of common salt and ten other alkali halides—compounds of lithium, sodium, potassium and rubidium, with fluorine, chlorine and bromine. He described the results as "exactly in accord with Bohr's recent views of the relation between electron structure and the periodic table". This brought Slater's observation concerning the mechanical properties of ionic crystals into line with the theory that Bohr had based on the spectroscopy of gaseous elements. He wrote the alkali halide paper in 1923, having "by the summer of 1922" been "thoroughly indoctrinated ... with quantum theory", in part by the courses of Edwin Kemble
Edwin C. Kemble
Edwin Crawford Kemble was an American physicist who made contributions to the theory of quantum mechanics and molecular structure and spectroscopy...

 following a fascination with Bohr's work during his undergraduate days. In 1924, Slater went to Europe on a Harvard Sheldon Fellowship. After a brief stay at the University of Cambridge
University of Cambridge
The University of Cambridge is a public research university located in Cambridge, United Kingdom. It is the second-oldest university in both the United Kingdom and the English-speaking world , and the seventh-oldest globally...

, he went on to the University of Copenhagen
University of Copenhagen
The University of Copenhagen is the oldest and largest university and research institution in Denmark. Founded in 1479, it has more than 37,000 students, the majority of whom are female , and more than 7,000 employees. The university has several campuses located in and around Copenhagen, with the...

, where "he explained to Bohr
Niels Bohr
Niels Henrik David Bohr was a Danish physicist who made foundational contributions to understanding atomic structure and quantum mechanics, for which he received the Nobel Prize in Physics in 1922. Bohr mentored and collaborated with many of the top physicists of the century at his institute in...

 and Kramers
Hendrik Anthony Kramers
Hendrik Anthony "Hans" Kramers was a Dutch physicist.-Background and education:...

 his idea (that was) a sort of forerunner of the duality principle
Wave–particle duality
Wave–particle duality postulates that all particles exhibit both wave and particle properties. A central concept of quantum mechanics, this duality addresses the inability of classical concepts like "particle" and "wave" to fully describe the behavior of quantum-scale objects...

, (hence) the celebrated paper" on the work that others dubbed the Bohr-Kramers-Slater (BKS) theory
BKS theory
The Bohr-Kramers-Slater theory was perhaps the final attempt at understanding the interaction of matter and electromagnetic radiation on the basis of the so-called Old quantum theory, in which quantum phenomena are treated by imposing quantum restrictions on classically describable behaviour...

. "Slater suddenly became an internationally known name.". Slater discusses his early life through the trip to Europe in a transcribed interview.

Slater joined the Harvard faculty on his return from Europe in 1925, then moved to MIT in 1930. His research papers covered many topics. A year by year selection, up to his switch to work relating to radar includes:
  • 1924: the theoretical part of his Ph.D. work, the Bohr-Kramers-Slater (BKS) theory
    BKS theory
    The Bohr-Kramers-Slater theory was perhaps the final attempt at understanding the interaction of matter and electromagnetic radiation on the basis of the so-called Old quantum theory, in which quantum phenomena are treated by imposing quantum restrictions on classically describable behaviour...

    ,
  • 1925: widths of spectral lines
    Spectral linewidth
    The spectral linewidth characterizes the width of a spectral line, such as in the electromagnetic emission spectrum of an atom, or the frequency spectrum of an acoustic or electronic system...

    ; ideas that came very close to the electron spins principle,
  • 1926 and 1927: explicit attention to electron spin, and to the Schrödinger equation
    Schrödinger equation
    The Schrödinger equation was formulated in 1926 by Austrian physicist Erwin Schrödinger. Used in physics , it is an equation that describes how the quantum state of a physical system changes in time....

    ;
  • 1928: the Hartree self-consistent field, the Rydberg formula
    Rydberg formula
    The Rydberg formula is used in atomic physics to describe the wavelengths of spectral lines of many chemical elements. It was formulated by the Swedish physicist Johannes Rydberg, and presented on November 5, 1888.-History:...

    ,
  • 1929: the determinantal expression
    Slater determinant
    In quantum mechanics, a Slater determinant is an expression that describes the wavefunction of a multi-fermionic system that satisfies anti-symmetry requirements and consequently the Pauli exclusion principle by changing sign upon exchange of fermions . It is named for its discoverer, John C...

     for an antisymmetric wave function,
  • 1930: Slater type orbitals
    Slater-type orbital
    Slater-type orbitals are functions used as atomic orbitals in the linear combination of atomic orbitals molecular orbital method. They are named after the physicist John C. Slater, who introduced them in 1930....

     (STOs) and atomic shielding constants,
  • 1931: linear combination of atomic orbitals
    Molecular orbital
    In chemistry, a molecular orbital is a mathematical function describing the wave-like behavior of an electron in a molecule. This function can be used to calculate chemical and physical properties such as the probability of finding an electron in any specific region. The term "orbital" was first...

    ,; van der Waals force
    Van der Waals force
    In physical chemistry, the van der Waals force , named after Dutch scientist Johannes Diderik van der Waals, is the sum of the attractive or repulsive forces between molecules other than those due to covalent bonds or to the electrostatic interaction of ions with one another or with neutral...

    s (with Jack Kirkwood
    John Gamble Kirkwood
    John "Jack" Gamble Kirkwood was a noted chemist and physicist, holding faculty positions at Cornell University, the University of Chicago, California Institute of Technology, and Yale University.-Early life and background:Kirkwood was born in Gotebo, Oklahoma, the oldest child of John Millard and...

    , as a Chemistry Research Associate).
  • 1932 to 1935: atomic orbitals, metallic conduction, application of the Thomas–Fermi method to metals,
  • 1936: ferromagnetism
    Ferromagnetism
    Ferromagnetism is the basic mechanism by which certain materials form permanent magnets, or are attracted to magnets. In physics, several different types of magnetism are distinguished...

    , (with Erik Rudberg, later Chairman of the Nobel Prize committee for Physics
    Nobel Committee for Physics
    The Nobel Committee for Physics is the Nobel Committee responsible for proposing laureates for the Nobel Prize for Physics. The Nobel Committee for Physics is appointed by the Royal Swedish Academy of Sciences...

    ) inelastic scattering
    Inelastic scattering
    In particle physics and chemistry, inelastic scattering is a fundamental scattering process in which the kinetic energy of an incident particle is not conserved . In an inelastic scattering process, some of the energy of the incident particle is lost or gained...

    , and (with his Ph.D. student William Shockley
    William Shockley
    William Bradford Shockley Jr. was an American physicist and inventor. Along with John Bardeen and Walter Houser Brattain, Shockley co-invented the transistor, for which all three were awarded the 1956 Nobel Prize in Physics.Shockley's attempts to commercialize a new transistor design in the 1950s...

     and close to his own Ph.D. topic), optical properties of alkali halides
  • 1937 and 1938: augmented plane waves
    Electronic band structure
    In solid-state physics, the electronic band structure of a solid describes those ranges of energy an electron is "forbidden" or "allowed" to have. Band structure derives from the diffraction of the quantum mechanical electron waves in a periodic crystal lattice with a specific crystal system and...

    , superconductivity
    Superconductivity
    Superconductivity is a phenomenon of exactly zero electrical resistance occurring in certain materials below a characteristic temperature. It was discovered by Heike Kamerlingh Onnes on April 8, 1911 in Leiden. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum...

    , ferromagnetism
    Ferromagnetism
    Ferromagnetism is the basic mechanism by which certain materials form permanent magnets, or are attracted to magnets. In physics, several different types of magnetism are distinguished...

    , electrodynamics,
  • 1939 he published "only" a book: the definitive Introduction to Chemical Physics,
  • 1940 the Grüneisen constant
    Grüneisen Parameter
    The Grüneisen parameter, γ, named after Eduard Grüneisen, describes the effect that changing the volume of a crystal lattice has on its vibrational properties, and, as a consequence, the effect that changing temperature has on the size or dynamics of the lattice...

    , and the Curie point
    Curie point
    In physics and materials science, the Curie temperature , or Curie point, is the temperature at which a ferromagnetic or a ferrimagnetic material becomes paramagnetic on heating; the effect is reversible. A magnet will lose its magnetism if heated above the Curie temperature...

    ,
  • 1941 phase change analogous to ferromagnetism
    Ferromagnetism
    Ferromagnetism is the basic mechanism by which certain materials form permanent magnets, or are attracted to magnets. In physics, several different types of magnetism are distinguished...

     in potassium dihydrogen phosphate
    Monopotassium phosphate
    Monopotassium phosphate -- 24 -- is a soluble salt which is used as a fertilizer, a food additive and a fungicide. It is a source of phosphorus and potassium. It is also a buffering agent...

    .


In his memoir, Morse wrote "In addition to other notable papers ... on ... Hartree's self-consistent field, the quantum mechanical derivation of the Rydberg constant
Rydberg constant
The Rydberg constant, symbol R∞, named after the Swedish physicist Johannes Rydberg, is a physical constant relating to atomic spectra in the science of spectroscopy. Rydberg initially determined its value empirically from spectroscopy, but Niels Bohr later showed that its value could be calculated...

, and the best values of atomic shielding constants
Shielding effect
The shielding effect describes the decrease in attraction between an electron and the nucleus in any atom with more than one electron shell. It is also referred to as the screening effect or atomic shielding.-Cause:...

, he wrote a seminal paper on directing valency " (what became known, later, as linear combination of atomic orbitals
Molecular orbital
In chemistry, a molecular orbital is a mathematical function describing the wave-like behavior of an electron in a molecule. This function can be used to calculate chemical and physical properties such as the probability of finding an electron in any specific region. The term "orbital" was first...

).
In further comments, John Van Vleck
John Hasbrouck van Vleck
John Hasbrouck Van Vleck was an American physicist and mathematician, co-awarded the 1977 Nobel Prize in Physics, for his contributions to the understanding of the behavior of electrons in magnetic solids....

 pays particular attention to (1) the 1925 study of the spectra of hydrogen and ionized helium, that J.V.V. considers one sentence short of proposing electron spin (which would have led to sharing a Nobel prize), and (2) what J.V.V. regards as Slater's greatest paper, that introduced the mathematical object now called the Slater determinant. "These were some of the achievements (that led to his) election to the National Academy ... at ... thirty-one. He played a key role in lifting American theoretical physics to high international standing." Slater's doctoral students, during this time, included Nathan Rosen
Nathan Rosen
Nathan Rosen was an American-Israeli physicist noted for his study on the structure of the hydrogen molecule and his work with Albert Einstein and Boris Podolsky on entangled wave functions and the EPR paradox.-Background:Nathan Rosen was born into a Jewish family in Brooklyn, New York...

 Ph.D. in 1932 for a theoretical study of the hydrogen molecule, and William Shockley
William Shockley
William Bradford Shockley Jr. was an American physicist and inventor. Along with John Bardeen and Walter Houser Brattain, Shockley co-invented the transistor, for which all three were awarded the 1956 Nobel Prize in Physics.Shockley's attempts to commercialize a new transistor design in the 1950s...

 Ph.D. 1936 for an energy band structure of sodium chloride, who later received a Nobel Prize for the discovery of the transistor.

Research during the war and the return to peace time activities


Slater, in his experimental and theoretical work on the magnetron (key elements paralleled his prior work with self-consistent fields for atoms) and on other topics at the Radiation Laboratory and at the Bell Laboratories did "more than any other person to provide the understanding requisite to progress in the microwave field", in the words of Mervin Kelley, then head of Bell Labs, quoted by Morse.

Slater' publications during the war and the post-war recovery include a book and papers on microwave transmission
Microwave transmission
Microwave transmission refers to the technology of transmitting information or power by the use of radio waves whose wavelengths are conveniently measured in small numbers of centimeters; these are called microwaves. This part of the radio spectrum ranges across frequencies of roughly...

 and microwave electronics, linear accelerators, cryogenics
Cryogenics
In physics, cryogenics is the study of the production of very low temperature and the behavior of materials at those temperatures. A person who studies elements under extremely cold temperature is called a cryogenicist. Rather than the relative temperature scales of Celsius and Fahrenheit,...

, and, with Francis Bitter
Francis Bitter
Francis Bitter was an American physicist.Bitter invented the Bitter plate used in resistive magnets . He is the one who thought of using dust to visualize a magnetic field...

 and several other colleagues, superconductors, These publications credit the many other scientists, mathematicians and engineers who participated. Among these,
George H. Vineyard received his Ph.D. with Slater in 1943 for a study of space charge in the cavity magnetron. Later, he became Director of the Brookhaven National Laboratory and President of the American Physical Society. The work of the Radiation Laboratory paralleled research at the Telecommunications Research Establishment
Telecommunications Research Establishment
The Telecommunications Research Establishment was the main United Kingdom research and development organization for radio navigation, radar, infra-red detection for heat seeking missiles, and related work for the Royal Air Force during World War II and the years that followed. The name was...

 in England and the groups maintained a productive liaison.

Activities


In the words of Robert Nesbet: "Slater founded the SSMTG with the idea of bringing together a younger generation of students and PostDocs with a common interest in the electronic structure and properties of atoms, molecules and solids. This was in part to serve as a balance for electronic physics to survive the overwhelming growth of nuclear physics following the war" .

George Koster soon completed his Ph.D., joined the faculty, and became the senior member of the group. He wrote "During the fifteen-year life of the group some sixty persons were members and thirty-four took doctoral degrees with theses connected with its work. In my report I have been unable to separate the work of Slater from that of the group as a whole. He was part of every aspect of the group's research efforts."

Nesbet continued "Every morning in SSMTG began with a coffee session, chaired by Professor Slater, with the junior members seated around a long table ... Every member of the group was expected to contribute a summary of his own work and ideas to the Quarterly Progress Report". The SMMTG QPRs had a wide distribution to university and industrial research libraries, and to individual laboratories. They were quoted widely for scientific and biographical content, in journal articles and government reports and libraries are starting to put them online.

To begin the work of the group, Slater "distilled his experience with the Hartree self-consistent field method" into (1) a simplification that became known as the Xα method, and (2) a relationship between a feature of this method and a magnetic property of the system. These required computations that were excessive for "pencil and paper" work. Slater was quick to avail the SSMTG of the electronic computers that were being developed. An early paper on augmented plane waves used an IBM card programmed calculator. The Whirlwind
Whirlwind (computer)
The Whirlwind computer was developed at the Massachusetts Institute of Technology. It is the first computer that operated in real time, used video displays for output, and the first that was not simply an electronic replacement of older mechanical systems...

 was used heavily, then the IBM 704 in the MIT Computation Center
M.I.T. Computation Center
-History of the M.I.T. Computation Center:The M.I.T. Computation Center, organized in 1956, housed an IBM 704 up until 1960.-The M.I.T. Computation Center and Operation Moonwatch:...

 and then the IBM 709 in the Cooperative Computing Laboratory (see below).

Solid state work progressed more rapidly at first in the SSMTG, with contributions over the first few years by George Koster, John Wood, Arthur Freeman and Leonard Mattheis. Molecular and atomic calculations also flourished in the hands of Fernando J. Corbató
Fernando J. Corbató
Fernando José "Corby" Corbató is a prominent American computer scientist, notable as a pioneer in the development of time-sharing operating systems....

, Lee Allen and Alvin Meckler. This initial work followed lines largely set by Slater. Michael Barnett came in 1958. He and John Wood were given faculty appointments. Robert Nesbet, Brian Sutcliffe, Malcolm Harrison and Levente Szasz brought in a variety of further approaches to molecular and atomic problems. Jens Dahl, Alfred Switendick, Jules Moskowitz, Donald Merrifield
Donald Merrifield
Donald Paul Merrifield, S.J., Ph.D. was an American Jesuit who served as both the 11th president of former Loyola University and remained president during and after the school's merger with Marymount College when its name became Loyola Marymount University in 1973. Merrifield remained the...

 and Russell Pitzer
Russell M. Pitzer
Russell Mosher Pitzer is an American theoretical chemist and educator.He was born on May 10, 1938, in Berkeley, California and attended public schools in this and the Washington, DC area....

 did further work on molecules, and Fred Quelle on solids.

Slater rarely included his name on the papers of SSMTG members who worked with him. Major pieces of work which he did coauthor dealt with applications of (1) group theory in band structure calculations and (2) equivalent features of linear combination of atomic orbital (LCAO)
Molecular orbital
In chemistry, a molecular orbital is a mathematical function describing the wave-like behavior of an electron in a molecule. This function can be used to calculate chemical and physical properties such as the probability of finding an electron in any specific region. The term "orbital" was first...

, tight binding and Bloch wave
Bloch wave
A Bloch wave or Bloch state, named after Felix Bloch, is the wavefunction of a particle placed in a periodic potential...

 approximations, to interpolate results for the energy levels of solids, obtained by more accurate methods,

People


A partial list of members of the SSMTG (Ph.D. students, post-doctoral members, research staff and faculty, in some cases successively, labeled †, ‡, ৳, ¶), together with references that report their SSMTG and later activities, follows.
  • Leland C. Allen †‡, ab initio
    Ab initio quantum chemistry methods
    Ab initio quantum chemistry methods are computational chemistry methods based on quantum chemistry. The term ab initiowas first used in quantum chemistry by Robert Parr and coworkers, including David Craig in a semiempirical study on the excited states of benzene.The background is described by Parr...

     molecular calculations, electronegativity
    Electronegativity
    Electronegativity, symbol χ , is a chemical property that describes the tendency of an atom or a functional group to attract electrons towards itself. An atom's electronegativity is affected by both its atomic number and the distance that its valence electrons reside from the charged nucleus...

    , Professor of Chemistry Emeritus, Princeton University (2011).
  • Michael P Barnett ৳¶, molecular integrals, software, phototypesetting
    Phototypesetting
    Phototypesetting was a method of setting type, rendered obsolete with the popularity of the personal computer and desktop publishing software, that uses a photographic process to generate columns of type on a scroll of photographic paper...

    , cognition, later in industry, Columbia U. and CUNY.
  • Louis Burnelle‡, molecular calculations, later Professor of Chemistry, New York University.
  • Earl Callen †
  • Fernando J. Corbató
    Fernando J. Corbató
    Fernando José "Corby" Corbató is a prominent American computer scientist, notable as a pioneer in the development of time-sharing operating systems....

     †, began the molecular calculations in the SSMTG; later a pioneer of time-sharing
    Time-sharing
    Time-sharing is the sharing of a computing resource among many users by means of multiprogramming and multi-tasking. Its introduction in the 1960s, and emergence as the prominent model of computing in the 1970s, represents a major technological shift in the history of computing.By allowing a large...

     and recipient of Turing award
    Turing Award
    The Turing Award, in full The ACM A.M. Turing Award, is an annual award given by the Association for Computing Machinery to "an individual selected for contributions of a technical nature made to the computing community. The contributions should be of lasting and major technical importance to the...

    .
  • George Coulouris
    George Coulouris (computer scientist)
    George Coulouris is a British computer scientist and the son of actor George Coulouris. He is an emeritus professor of Queen Mary, University of London and is currently Visiting Professor in Residence at University of Cambridge Computer Laboratory and co-author of a...

     ৳, worked with MPB, later Professor of Computer Science at Queen Mary College of the University of London.
  • Imre Cszimadia ‡, molecular calculations (LiH), later Professor of Chemistry, U. Toronto, ab initio calculations, drug design.
  • Jens Dahl ‡, molecular calculations, later Professor of Chemistry, Technical University of Denmark,wrote quantum chemistry text.
  • Donald E. Ellis ৳†, molecular calculations, later Professor of Physics and Astronomy at North Western University, "real" materials.
  • Arthur Freeman †‡, orthogonalized plane wave calculations, later Professor of Physics and Astronomy at North Western University
  • Robert P. Futrelle ৳, programming methods, later Professor of Computer and Information Science at North Eastern University.
  • Malcolm Harrison ‡, (died 2007) co-developer of POLYATOM, later Professor of Computer Science, New York University.
  • Frank Herman, band structure calculations, went into RCA then IBM Research Laboratories, wrote and edited major surveys.
  • David Howarth ‡, solid state, later Professor of Computer Science, Imperial College, University of London.
  • John Iliffe
    Iliffe vector
    In computer programming, an Iliffe vector, also known as a display, is a data structure used to implement multi-dimensional arrays. An Iliffe vector for an n-dimensional array consists of a vector of pointers to an -dimensional array...

     ৳, computer scientist.
  • San-Ichiro Ishigura ‡, later Professor, Ochinamizu University
  • Arnold Karo ‡, electronic structure of small molecules, later at Lawrence Livermore Laboratory.
  • C.W. Kern ‡, molecular calculations, later Professor of Chemistry, Ohio State U., published extensively.
  • Ryoichi Kikuchi ‡
  • Walter H. Kleiner, solid state physics, continued at Lincoln Laboratory.
  • George F. Koster †¶, became Chairman of the Physics Graduate Committee at MIT and wrote two books on solid state physics.
  • Leonard F. Mattheiss †, augmented plane wave calculations, later at Bell Labs, published about 100 papers.
  • Roy McWeeny
    Roy McWeeny
    Roy McWeeny, born May 19, 1924 in Bradford, Yorkshire, England, is a physicist and academic.His first degree is in Physics from the University of Leeds...

     ‡, valence theory, later held chairs at several British Universities and, since 1982, at the University of Pisa
    University of Pisa
    The University of Pisa , located in Pisa, Tuscany, is one of the oldest universities in Italy. It was formally founded on September 3, 1343 by an edict of Pope Clement VI, although there had been lectures on law in Pisa since the 11th century...

    , Italy.
  • Alvin Meckler, first major molecular calculation on Whirlwind (oxygen), later National Security Agency,
  • Donald Merrifield
    Donald Merrifield
    Donald Paul Merrifield, S.J., Ph.D. was an American Jesuit who served as both the 11th president of former Loyola University and remained president during and after the school's merger with Marymount College when its name became Loyola Marymount University in 1973. Merrifield remained the...

     †, molecular calculations (methane), later President of Loyola University, Los Angeles.
  • Jules Moskowitz ‡, molecular calculations (benzene), later Chairman, Department of Chemistry, NYU, published 100 papers.
  • Robert K. Nesbet ‡, molecular calculations, later at IBM Almaden Research Laboratories, published over 200 papers.
  • Robert H. Parmenter, later Professor of Physics, U. Arizona, crystal properties and superconductivity.
  • Russell M. Pitzer
    Russell M. Pitzer
    Russell Mosher Pitzer is an American theoretical chemist and educator.He was born on May 10, 1938, in Berkeley, California and attended public schools in this and the Washington, DC area....

     ‡, molecular calculations (ethane), later Chairman of Chemistry Department, Ohio State U, over 100 papers.
  • George W. Pratt, Jr. †‡later Professor of Electrical Engineering and CMSE
    CMSE
    CMSE is an accredited specialist in environmental, safety and energy consultancy and training services. The company is retained by organisations in Ireland and the UK to ensure compliance, minimise risk and upskill management and staff....

    , MIT, solid state electronics.
  • F.W. Quelle, Jr. augemented plane waves, later laser optics.
  • Melvin M. Saffren †
  • Robert Schrieffer
    John Robert Schrieffer
    John Robert Schrieffer is an American physicist and, with John Bardeen and Leon N Cooper, recipient of the 1972 Nobel Prize for Physics for developing the BCS theory, the first successful microscopic theory of superconductivity.-Biography:...

     wrote Bachelor's thesis on multiplets in heavy atoms, later shared Nobel Prize for BCS theory.
  • Edward Schultz
  • Harold Schweinler
  • Hermann Statz ‡, ferromagnetism, later director of research at Raytheon and recipient of 2004 IEEE Microwave Pioneer Award,
  • Levente Szasz, atomic structure, became Professor of Physics at Fordham University, published two books,
  • Brian T. Sutcliffe ‡, co-developer of POLYATOM, later Professor of Chemistry, University of York.
  • Richard E. Watson ‡៛, electronic properties of metal atoms, later at Brookhaven, published over 200 papers.
  • E.B. White †
  • John Wood †¶, augmented plane waves using Hartree-Fock methods, at Los Alamos National Laboratory (died 1986), published extensively.


Distinguished visitors included Frank Boys
S. Francis Boys
Samuel Francis Boys FRS was born in Pudsey, Yorkshire, England. He was educated at the Grammar School in Pudsey and then at Imperial College, London. He graduated in Chemistry in 1932. He did his Ph.D...

, Alex Dalgarno, V. Fano, Anders Fröman, Inge Fischer-Hjalmars, Douglas Hartree
Douglas Hartree
Douglas Rayner Hartree PhD, FRS was an English mathematician and physicist most famous for the development of numerical analysis and its application to the Hartree-Fock equations of atomic physics and the construction of the meccano differential analyser.-Early life:Douglas Hartree was born in...

, Werner Heisenberg
Werner Heisenberg
Werner Karl Heisenberg was a German theoretical physicist who made foundational contributions to quantum mechanics and is best known for asserting the uncertainty principle of quantum theory...

, Per-Olov Löwdin
Per-Olov Löwdin
Per-Olov Löwdin was a Swedish physicist, professor at the University of Uppsala from 1960 to 1983, and in parallel at the University of Florida until 1993....

, Chaim Pekeris
Chaim L. Pekeris
Chaim Leib Pekeris was an Israeli-American physicist and mathematician. He made notable contributions to geophysics and the spectral theory of many-electron atoms, in particular the Helium atom. He was also one of the designers of the first computer in Israel, WEIZAC.-Biography:Pekeris was bon in...

, Ivar Waller
Ivar Waller
Ivar Waller was a Swedish professor of theoretical physics at Uppsala University. He developed the theory of X-ray scattering by lattice vibrations of a crystal, building upon the prior work of Peter Debye...

 and Peter Wohlfarth
Erich Peter Wohlfarth
Erich Peter Wohlfarth was a theoretical physicist. He is known for his work in magnetism, in particular the Stoner–Wohlfarth model he developed together with his teacher E.C. Stoner....

.

Slater's further activities at MIT during this time


In the 1962 President's Report, Jay Stratton wrote (on p. 17) "A faculty committee under the chairmanship of Professor John C. Slater has taken primary responsibility for planning the facilities in the new Center for Materials. These include a new Cooperative Computing Laboratory completed this year and equipped with an I.B.M. 709 Computer".

The name Center for Materials Science and Engineering (CMSE) was adopted soon afterward. It embodied the ethos of interdepartmental research and teaching that Slater had espoused throughout his career. The first Director was R.A. Smith, previously Head of the Physics Division of the Royal Radar Establishment
Royal Radar Establishment
The name Royal Radar Establishment was given to the existing Radar Research Establishment following a visit by Queen Elizabeth II in 1957. Both names were abbreviated to RRE. The establishment had been formed, under its first name, in 1953 by merging the Telecommunications Research Establishment ...

 in England. He, Slater and Charles Townes, the Provost, had been in close acquaintance since the early years of World War II, working on overlapping topics.

The Center was set up, in accordance with Slater's plans. It "supported research and teaching in Metallurgy and Materials Science, Electrical Engineering, Physics, Chemistry and Chemical Engineering", and preserved MIT as a focus for work in solid state physics. By 1967, two years after Slater left, the MIT Physics Department "had a very, very small commitment to condensed matter physics" because it was so "heavily into high energy physics." But in the same year, the CMSE staff included 55 professors and 179 graduate students. The Center continues to flourish in the 21st century.

The Cooperative Computing Laboratory (CCL) was used, in its first year by some 400 faculty, students and staff. These included (1) members of the SSMTG and the CCL running quantum mechanical calculations and non-numeric applications directed by Slater, Koster, Wood and Barnett, (2) the computer-aided design team of Ross
Douglas T. Ross
Douglas Taylor Ross was an American computer scientist pioneer, and Chairman of SofTech, Inc.. He is most famous for originating the term CAD for computer-aided design, and is consider to be the father of Automatically Programmed Tools a language to drive numerically controlled manufacturing.-...

, Coons and Mann, (3) members of the Laboratory for Nuclear Science, (4) Charney and Phillips in theoretical meteorology, and (5) Simpson and Madden in geophysics (from 1964 President's report, p. 336-337).

The final years


John was divorced and in 1954 he married Dr. Rose Mooney, a physicist, who moved to Florida with him in 1965.

At the University of Florida (Gainsville) where the retirement age was 70, Slater was able to enjoy another five years of active research and publication as a Research Professor in the Quantum Theory Project (QTP). In 1975, in his scientific autobiography, he wrote: ""The Florida Physics Department was a congenial one, with main emphasis on solid state physics, statistical physics and related fields. It reminded me of the MIT department in the days when I had been department head there. It was a far cry from the MIT Physics Department which I was leaving; by then it had been literally captured by the nuclear theorists." Slater published to the end of his life: his final journal paper, published with John Connolly in 1976, was on a novel approach to molecular orbital theory.

John Slater died in Sanibel Island, Florida in 1976.

As an educator and advisor


Slater's concern for the well being of others is well illustrated by the following dialog that Richard Feynman
Richard Feynman
Richard Phillips Feynman was an American physicist known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics and the physics of the superfluidity of supercooled liquid helium, as well as in particle physics...

 relates. It took place at the end of his undergraduate days at MIT, when he wanted to stay on to do a Ph.D. "When I went to Professor Slater and told him of my intentions he said: 'We will not have you here'. I said 'What?' Slater said 'Why do you think you should go to graduate school at MIT?' 'Because it is the best school for science in the country' ... 'That is why you should go to some other school. You should find out how the rest of the world is.' So I went to Princeton. ... Slater was right. And I often advise my students the same way. Learn what the rest of the world is like. The variety is worth while."

Summary


From the memoir by Philip Morse: "He contributed significantly to the start of the quantum revolution in physics; he was one of the very few American-trained physicists to do so. He was exceptional in that he persisted in exploring atomic, molecular and solid state physics, while many of his peers were coerced by war, or tempted by novelty, to divert to nuclear mysteries. Not least, his texts and his lectures contributed materially to the rise of the illustrious American generation of physicists of the 1940s and 1950s."

But that was not the end. The new generation that Slater launched from the SSMTG and the QTP took knowledge and skills into departments of Physics and Chemistry and Computer Science, into industrial and government laboratories and academe, into research and administration. They have continued and evolved his methodologies, applying them to an increasing variety of topics from atomic energy levels to drug design, and to a host of solids and their properties. Slater imparted knowledge and advice, and he recognized new trends, provided financial support from his grants, and motivational support by sharing the enthusiasms of the protagonists.

In a slight paraphrase of a recent and forward looking comment of John Connolly, it can be said that the contributions of John C. Slater and his students in the SSMTG and the Quantum Theory Project laid the foundations of density functional theory
Density functional theory
Density functional theory is a quantum mechanical modelling method used in physics and chemistry to investigate the electronic structure of many-body systems, in particular atoms, molecules, and the condensed phases. With this theory, the properties of a many-electron system can be determined by...

 which has become one of the premier approximations in quantum theory today.

Slater's papers were bequeathed to the American Philosophical Society
American Philosophical Society
The American Philosophical Society, founded in 1743, and located in Philadelphia, Pa., is an eminent scholarly organization of international reputation, that promotes useful knowledge in the sciences and humanities through excellence in scholarly research, professional meetings, publications,...

by his widow, Rose Mooney Slater, in 1980 and 1982. In August 2003, Alfred Switendick donated a collection of Quarterly Reports of the MIT Solid State and Molecular Theory Group (SSMTG), dating from 1951 to 1965. These are available in several major research libraries.