Size versus volume extensivity of a new class of density matrix functionals.
Despite being size-extensive, the "second-generation" 1-matrix functionals for the electron-electron repulsion energy V(ee) yield vanishing correlation energy for the homogeneous electron gas. This failure is directly related to the idempotency condition imposed upon an auxiliary matrix that enters the expression for V(ee). In particular, the recently proposed Kollmar-Hess functional is not volume-extensive and thus is incapable of properly describing any delocalized system at its thermodynamic limit.
Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-3006, USA. jerzy@kyoko.chem.fsu.edu
Jerzy
J
Cioslowski
Katarzyna
K
Pernal