Spin-1/2 Decoupling Procedures in the First-Order Green's-Function Theory of Ferromagnetism

1973 ◽  
Vol 7 (11) ◽  
pp. 4941-4950 ◽  
Author(s):  
M. D. Coutinho Filho ◽  
I. P. Fittipaldi
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Function Theory ◽  
First Order

Eine Approximation der Löwdinschen natürlichen Orbitale für Moleküle mit einer Green-Funktion-Methode

1972 ◽  
Vol 27 (4) ◽  
pp. 545-552 ◽  
Author(s):  
R. Albat
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Mass Operator ◽  
Ground States ◽  
Present Form ◽  
Many Body ◽  
Natural Orbitals ◽  
First Order ◽  
The Many ◽  
Closed Shells

Abstract An Approximation of Löwdin's Natural Orbitals for Molecules with a Green's Function Method The many-body-pertubation theorie of the single-particle Green's function is used to get an approximate first-order density matrix. Slightly modified SCF-orbitals form the basis for the expansion. The mass-operator in Dyson's equation is considered up to second order in the Perturbation. In the present form the method is only applicable to ground states with closed shells. The ground states of the molecules LiH and NH3 serve as examples to demonstrate the usefulness of the directly calculated natural orbitals for application in the C I-method. The natural orbitals give a much better convergence of the C I-expansion than the SCF-orbitals do.

scholarly journals Green's Function Theory of Magnetic Relaxation. II

1963 ◽  
Vol 29 (5) ◽  
pp. 651-674 ◽  
Author(s):  
Motoyuki Tanaka ◽  
Kazuhisa Tomita
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Magnetic Relaxation ◽  
Function Theory
Sign in / Sign up

Export Citation Format

Share Document