title: An efficient algorithm for complete active space valence bond self-consistent field calculation.
abstract: This article describes a novel algorithm for the optimization of valence bond self-consistent field (VBSCF) wave function for a complete active space (CAS), so-called VBSCF(CAS). This was achieved by applying the strategies adopted in the optimization of CASSCF wave functions to VBSCF(CAS) wave functions, using an auxiliary orthogonal orbital set that generates the same configuration space as the original nonorthogonal orbital set. Theoretical analyses and test calculations show that the VBSCF(CAS) method shares the same computational scaling as CASSCF. The test calculations show the current capability of VBSCF method, which involves millions of VB structures.
authors.affiliation: The State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China.
authors.forename: Jinshuai
authors.initials: J
authors.lastname: Song
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Chen
authors.forename: Sason
authors.initials: S
authors.lastname: Shaik
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
mesh_terms: D000465:Algorithms; D011789:Quantum Theory