Multiplicity (chemistry)
Encyclopedia
Multiplicity in quantum chemistry
is used to distinguish between several degenerate wavefunction
s that differ only in the orientation of their angular spin momenta
. It is defined as 2S+1, where S is the angular spin momentum.
Multiplicity is the quantification of the amount of unpaired electron spin. Multiplicity is a
result of Hund's rule which favors the single filling of degenerate (same energy) orbitals.
The result is the filling of multiple orbitals with electrons or multiplicity. Multiplicity is
calculated with the equation: 2 S + 1 (where S = Σms or more simply put, S = ½(# of unpaired electrons). When all electrons are paired S = 0, and the multiplicity = 2(0) + 1 = 1. This case is called a singlet. If a molecule has 1 unpaired electron S = +½ and 2S + 1 = 2, which is called a doublet. Two unpaired electrons would result in a triplet, etc.
Quantum chemistry
Quantum chemistry is a branch of chemistry whose primary focus is the application of quantum mechanics in physical models and experiments of chemical systems...
is used to distinguish between several degenerate wavefunction
Wavefunction
Not to be confused with the related concept of the Wave equationA wave function or wavefunction is a probability amplitude in quantum mechanics describing the quantum state of a particle and how it behaves. Typically, its values are complex numbers and, for a single particle, it is a function of...
s that differ only in the orientation of their angular spin momenta
Spin (physics)
In quantum mechanics and particle physics, spin is a fundamental characteristic property of elementary particles, composite particles , and atomic nuclei.It is worth noting that the intrinsic property of subatomic particles called spin and discussed in this article, is related in some small ways,...
. It is defined as 2S+1, where S is the angular spin momentum.
Multiplicity is the quantification of the amount of unpaired electron spin. Multiplicity is a
result of Hund's rule which favors the single filling of degenerate (same energy) orbitals.
The result is the filling of multiple orbitals with electrons or multiplicity. Multiplicity is
calculated with the equation: 2 S + 1 (where S = Σms or more simply put, S = ½(# of unpaired electrons). When all electrons are paired S = 0, and the multiplicity = 2(0) + 1 = 1. This case is called a singlet. If a molecule has 1 unpaired electron S = +½ and 2S + 1 = 2, which is called a doublet. Two unpaired electrons would result in a triplet, etc.