Chemistry Reference
In-Depth Information
distribution
1
in the field provided by all nuclei in the molecule, and the
third is the average electronic repulsion of an electron pair described by
the pair function
r
r
2
.
Lastly, it is important to stress that the integral in (6.51) would involve
N(N!)
2
4N-dimensional integrations, which are reduced to a simple four-
dimensional space-spin integration by use of the density matrix! General
rules for the evaluation of the integrals in (6.55) in the general case of two
different Slater determinants
0
built from orthonormal spin-
orbitals were first given by Slater (1931) and recast in density matrix
form by McWeeny (1960).
Y
and
Y
