New derivation and a k-particle generalization of SCF-type theories

✍ Scribed by Werner Kutzelnigg

• Publisher: John Wiley and Sons
• Year: 1980
• Tongue: English
• Weight: 306 KB
• Volume: 18
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/qua.560180103

✦ Synopsis

Abstract

A hierarchy of necessary conditions that an exact density matrix of a pure state or an ensemble has to satisfy is derived, namely the hermiticity of certain operators F^(k)^. For k = 1 this reduces to the well‐known Hartree‐Fock condition. It is then shown that the __k__th set of conditions is equivalent to stationarity of the energy with respect to unitary k‐particle transformations. k‐Particle generalizations of Hartree‐Fock theory are then discussed both in the spirit of k‐particle pseudoeigenvalue equations and in the framework of a Newton–Raphson‐type constructive scheme.