XMVB 2.0: A new version of Xiamen valence bond program

E-ISSN： 1097-461x|115|11|731-737

ISSN： 0020-7608

Source： INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY (ELECTRONIC), Vol.115, Iss.11, 2015-06, pp. : 731-737

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

Xiamen valence bond (XMVB), which is an ab initio nonorthogonal valence bond program, has been progressively developed and refined during the last 25 years. As the release of XMVB 1.0 in 2004, a number of significant enhancements and improvements have been made to the program. As a consequence, a new version, XMVB 2.0, has been released and will be described in this article. In XMVB 2.0, the nonorthogonal orbital‐based reduced density matrix approach for the valence bond (VB) theory is implemented, based on the second quantization scheme for nonorthogonal orbitals. The present article also describes the recently developed algorithms for orbital optimization in the VB self‐consist field (VBSCF) method, in which the internal contraction of wave function is used for computing energy gradients. Moreover, several newly implemented ab initio VB methods, such as VBSCF(CAS), internally contracted VB second‐order perturbation theory (icVBPT2), VB polarizable continuum model, VB effective fragment potential (VBECP), and density‐functional‐based VB, are briefly reviewed in this article. Finally, test calculations of several planar arenes, in which up to 18 active electrons are involved, are performed with XMVB 2.0. © 2014 Wiley Periodicals, Inc.