The standard formula for the expectation value 〈 over(S, ̂)2 〉 of the total spin operator for single determinant wave functions is transformed to a form in which it appears a physically reasonable sum of atomic and diatomic contributions. The result obtained is much similar to that of previous treatments of local spins, but is free from their difficulty: it does not assign any spins to the atoms in molecules treated by the closed shell RHF method.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry