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Density matrices for itinerant and localized electrons with and without external fields

Authors :
N. H. March
Source :
Journal of Mathematical Physics. 38:2037-2052
Publication Year :
1997
Publisher :
AIP Publishing, 1997.

Abstract

Forms of canonical (Bloch) and Dirac density matrices for free electrons with and without external applied fields are first considered. The basic tool employed is the Bloch equation with a one-electron Hamiltonian. Such an approach is used to obtain a perturbation theory to all orders for the idempotent Dirac density matrix when a common potential energy V(r) is switched on to originally free electrons. The relation to density functional theory is then considered and the exchange–correlation contribution Vxc(r) to V(r) is expressed in terms of first- and second-order density matrices following Holas and March. These latter density matrices are now for the fully interacting system and, in particular, the first-order density matrix is no longer idempotent, though it must still satisfy generalized Pauli Principle conditions. Reference is also made to a localized Wigner electron in a strong magnetic field.

Details

ISSN :
10897658 and 00222488
Volume :
38
Database :
OpenAIRE
Journal :
Journal of Mathematical Physics
Accession number :
edsair.doi...........f32f604301960a5833470c4bfc2a1b33