학술논문
Direct variational determination of the two-electron reduced density matrix for doubly occupied-configuration-interaction wave functions: The influence of three-index N-representability conditions.
Document Type
Article
Author
Source
Subject
*TWO-electron atoms
*GROUND state (Quantum mechanics)
*VARIATIONAL principles
*WAVE functions
*DENSITY matrices
*SEMIDEFINITE programming
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Language
ISSN
0021-9606
Abstract
This work proposes the variational determination of two-electron reduced density matrices corresponding to the ground state of N-electron systems within the doubly occupied-configurationinteraction methodology. The P,Q, and G two-index N-representability conditions have been extended to the T1 and T2 (T2') three-index ones and the resulting optimization problem has been addressed using a standard semidefinite program. We report results obtained from the doubly occupiedconfiguration-interaction method, from the two-index constraint variational procedure and from the two- and three-index constraint variational treatment. The discussion of these results along with a study of the computational cost demanded shows the usefulness of our proposal. [ABSTRACT FROM AUTHOR]