Robert Parr
Encyclopedia
Robert Ghormley Parr is a theoretical chemist
. He is a chemistry professor at the University of North Carolina at Chapel Hill.
magna cum laude from Brown University
in 1942, and then entered the University of Minnesota
, receiving a Ph. D. in physical chemistry
in 1947. He joined the faculty at Minnesota upon receiving his Ph. D. and remained there one year. In 1948 he moved to the Carnegie Institute of Technology
(now Carnegie Mellon University
) in Pittsburgh
, Pennsylvania
, becoming a full professor in 1957. In 1962 he moved to Johns Hopkins University
in Baltimore, Maryland, and in 1974 to the University of North Carolina at Chapel Hill
, where he received appointment to an endowed professorship in 1990 and where he now teaches.
chemist Rudolph Pariser
, Parr developed a method of computing approximate molecular orbital
s for pi electron systems, published in 1953. Since an identical procedure was derived by John A. Pople
the same year, it is generally referred to as the Pariser-Parr-Pople method or PPP method. The PPP method differed from existing structural chemistry thinking (which advocated maximum overlap principle) by advancing the concept of zero differential overlap approximation.
By 1978 Parr had realized that Density Functional Theory
(DFT) would be extremely useful in quantitative calculations of chemical and biological systems, especially those with high molecular weights. In 1988 Parr, Weitao Yang and Chengteh Lee produced an improved DFT method which could approximate the correlation energy of systems. The LYP functional theory is now one of the most-often cited papers in the chemical literature.
In 1963 Parr published Quantum Theory of Molecular Electronic Structure, one of the first books to apply quantum theory to chemical systems.
In 1989 he and Yang published Density Functional Theory of Atoms and Molecules, now considered the basic textbook on DFT.
Theoretical chemistry
Theoretical chemistry seeks to provide theories that explain chemical observations. Often, it uses mathematical and computational methods that, at times, require advanced knowledge. Quantum chemistry, the application of quantum mechanics to the understanding of valency, is a major component of...
. He is a chemistry professor at the University of North Carolina at Chapel Hill.
Career
Parr received an A. B. degreeAcademic degree
An academic degree is a position and title within a college or university that is usually awarded in recognition of the recipient having either satisfactorily completed a prescribed course of study or having conducted a scholarly endeavour deemed worthy of his or her admission to the degree...
magna cum laude from Brown University
Brown University
Brown University is a private, Ivy League university located in Providence, Rhode Island, United States. Founded in 1764 prior to American independence from the British Empire as the College in the English Colony of Rhode Island and Providence Plantations early in the reign of King George III ,...
in 1942, and then entered the University of Minnesota
University of Minnesota
The University of Minnesota, Twin Cities is a public research university located in Minneapolis and St. Paul, Minnesota, United States. It is the oldest and largest part of the University of Minnesota system and has the fourth-largest main campus student body in the United States, with 52,557...
, receiving a Ph. D. in physical chemistry
Physical chemistry
Physical chemistry is the study of macroscopic, atomic, subatomic, and particulate phenomena in chemical systems in terms of physical laws and concepts...
in 1947. He joined the faculty at Minnesota upon receiving his Ph. D. and remained there one year. In 1948 he moved to the Carnegie Institute of Technology
Carnegie Institute of Technology
The Carnegie Institute of Technology , is the name for Carnegie Mellon University’s College of Engineering. It was first called the Carnegie Technical Schools, or Carnegie Tech, when it was founded in 1900 by Andrew Carnegie who intended to build a “first class technical school” in Pittsburgh,...
(now Carnegie Mellon University
Carnegie Mellon University
Carnegie Mellon University is a private research university in Pittsburgh, Pennsylvania, United States....
) in Pittsburgh
Pittsburgh, Pennsylvania
Pittsburgh is the second-largest city in the US Commonwealth of Pennsylvania and the county seat of Allegheny County. Regionally, it anchors the largest urban area of Appalachia and the Ohio River Valley, and nationally, it is the 22nd-largest urban area in the United States...
, Pennsylvania
Pennsylvania
The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...
, becoming a full professor in 1957. In 1962 he moved to Johns Hopkins University
Johns Hopkins University
The Johns Hopkins University, commonly referred to as Johns Hopkins, JHU, or simply Hopkins, is a private research university based in Baltimore, Maryland, United States...
in Baltimore, Maryland, and in 1974 to the University of North Carolina at Chapel Hill
University of North Carolina at Chapel Hill
The University of North Carolina at Chapel Hill is a public research university located in Chapel Hill, North Carolina, United States...
, where he received appointment to an endowed professorship in 1990 and where he now teaches.
Achievements and awards
Working with DuPontDuPont
E. I. du Pont de Nemours and Company , commonly referred to as DuPont, is an American chemical company that was founded in July 1802 as a gunpowder mill by Eleuthère Irénée du Pont. DuPont was the world's third largest chemical company based on market capitalization and ninth based on revenue in 2009...
chemist Rudolph Pariser
Rudolph Pariser
Rudolph Pariser is a physical and polymer chemist. He was born in Harbin, China to merchant parents. He attended the Von Hindenburg Schule in Harbin, an American Missionary School in Beijing and American School in Tokyo...
, Parr developed a method of computing approximate molecular orbital
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...
s for pi electron systems, published in 1953. Since an identical procedure was derived by John A. Pople
John Pople
Sir John Anthony Pople, KBE, FRS, was a Nobel-Prize winning theoretical chemist. Born in Burnham-on-Sea, Somerset, England, he attended Bristol Grammar School. He won a scholarship to Trinity College, Cambridge in 1943. He received his B. A. in 1946. Between 1945 and 1947 he worked at the Bristol...
the same year, it is generally referred to as the Pariser-Parr-Pople method or PPP method. The PPP method differed from existing structural chemistry thinking (which advocated maximum overlap principle) by advancing the concept of zero differential overlap approximation.
By 1978 Parr had realized that 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...
(DFT) would be extremely useful in quantitative calculations of chemical and biological systems, especially those with high molecular weights. In 1988 Parr, Weitao Yang and Chengteh Lee produced an improved DFT method which could approximate the correlation energy of systems. The LYP functional theory is now one of the most-often cited papers in the chemical literature.
In 1963 Parr published Quantum Theory of Molecular Electronic Structure, one of the first books to apply quantum theory to chemical systems.
In 1989 he and Yang published Density Functional Theory of Atoms and Molecules, now considered the basic textbook on DFT.
Awards and honors
- Member of the International Academy of Quantum Molecular ScienceInternational Academy of Quantum Molecular ScienceThe International Academy of Quantum Molecular Science is an international scientific learned society covering all applications of quantum theory to chemistry and chemical physics. It was created in Menton in 1967. The founding members were Raymond Daudel, Per-Olov Löwdin, Robert G. Parr, John...
- 1967 - Co-founded (with 4 others) the International Academy of Quantum Molecular ScienceInternational Academy of Quantum Molecular ScienceThe International Academy of Quantum Molecular Science is an international scientific learned society covering all applications of quantum theory to chemistry and chemical physics. It was created in Menton in 1967. The founding members were Raymond Daudel, Per-Olov Löwdin, Robert G. Parr, John...
- 1994 - Winner of American Chemical SocietyAmerican Chemical SocietyThe American Chemical Society is a scientific society based in the United States that supports scientific inquiry in the field of chemistry. Founded in 1876 at New York University, the ACS currently has more than 161,000 members at all degree-levels and in all fields of chemistry, chemical...
's Irving Langmuir AwardIrving Langmuir AwardThe Irving Langmuir Award in Chemical Physics is awarded annually, in even years by the American Chemical Society and in odd years by the American Physical Society. The award is meant to recognize and encourage outstanding interdisciplinary research in chemistry and physics, in the spirit of Irving...
in Chemical Physics - 2004 - winner of United States National Academy of SciencesUnited States National Academy of SciencesThe National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...
Award in Chemical Sciences - 2009 - winner of American Chemical Society's Award in Theoretical Chemistry