ISSN:
0020-7608
Keywords:
broken symmetry
;
general spin orbitals
;
symmetry dilemma
;
spin symmetry
;
symmetry in density functional theory
;
Chemistry
;
Theoretical, Physical and Computational Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The Kohn-Sham (KS) procedure for variational minimization of the Hohenberg-Kohn density functional utilizes a one-particle reduced density matrix of assumed diagonal form, hence depends implicitly on a set of auxiliary states. Originally, the auxiliary state was assumed to be a single determinant with doubly occupied spin orbitals, i.e., of the same form as in “restricted” Hartree-Fock theory. The pragmatic and formal extension of the KS procedure to noninteger occupation numbers requires extension to more general forms of the auxiliary state or even its replacement by an auxiliary ensemble. Though attention has been given to the symmetry properties of the KS one-matrix, its spin and time-reversal symmetries have not been classified along the lines of Fukutome's treatment of the generalized Hartree-Fock problem. Here we show that, in the context of constrained search density functional theory (DFT), Fukutome's analysis goes through essentially unaltered. We then consider the broken symmetry consequences for the case that the KS one-matrix is restricted to a single-determinantal KS auxiliary state. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 69: 451-460, 1998
Type of Medium:
Electronic Resource
Permalink
