A well-scaling natural orbital theory

作者：Gebauer Ralph; Cohen Morrel H^*; Car Roberto^*

来源：Proceedings of the National Academy of Sciences, 2016, 113(46): 12913-12918.

DOI：10.1073/pnas.1615729113

• electronic structure
• correlation
• density matrix

We introduce an energy functional for ground-state electronic structure calculations. Its variables are the natural spin-orbitals of singlet many-body wave functions and their joint occupation probabilities deriving from controlled approximations to the two-particle density matrix that yield algebraic scaling in general, and Hartree-Fock scaling in its seniority-zero version. Results from the latter version for small molecular systems are compared with those of highly accurate quantum-chemical computations. The energies lie above full configuration interaction calculations, close to doubly occupied configuration interaction calculations. Their accuracy is considerably greater than that obtained from current density-functional theory approximations and from current functionals of the one-particle density matrix.

• 出版日期2016-11-15