scholarly journals Analytic energy gradients for multiconfigurational self-consistent field second-order quasidegenerate perturbation theory (MC-QDPT)

1998 ◽  
Vol 108 (14) ◽  
pp. 5660-5669 ◽  
Author(s):  
Haruyuki Nakano ◽  
Kimihiko Hirao ◽  
Mark S. Gordon
Keyword(s):  
Perturbation Theory ◽  
Second Order ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field

Pertubation Theory About Self-Consistent Field Solution in One-Dimensional Hubbard Model

2003 ◽  
Vol 17 (18n20) ◽  
pp. 3363-3366 ◽  
Author(s):  
A. N. Kocharian ◽  
C. Yang ◽  
Y. L. Chiang
Keyword(s):  
Perturbation Theory ◽  
Hubbard Model ◽  
Electron Concentration ◽  
Ground State ◽  
Second Order ◽  
Electron Interaction ◽  
Field Solution ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field

The accurate analytical and numerical calculations of the electronic band structure and ground state properties of strongly correlated electrons within the Hubbard model are performed by constructing convergent perturbation theory for general interaction strength and electron concentration. We test the developed perturbation approach about mean field solution in the extreme conditions of one dimensionality for entire parameter space of electron interaction U/t and electron concentration n. The many-body perturbation formalism up two second order about the generalized self-consistent field (GSCF) Hamiltonian goes beyond the range of applicability of standard perturbation theory by incorporating systematically the effect of the random-phase-type perturbation techniques and controlled expansion of the energy functional for general U/t and n. The second order perturbation correction vanishes at small and large U/t limit and performed calculations of the ground state energy show a next to the perfect numerical agreement with the Bethe-ansatz results.

Sign in / Sign up

Export Citation Format

Share Document