What is VB2000?

VB2000 is an ab initio electronic structure package for performing modern Valence Bond (VB) calculations based on a highly efficient VB algorithm—the so called Algebrant Algorithm. It has also a general implementation of the Group Function (GF) Theory, in which a large molecule is described in terms of its constituent parts of physically identifiable "electron groups".  The combination of the efficient VB algorithm and the general implementation GF theory in VB2000 makes it a useful tool for the investigation of the nature of chemical systems.

VB2000 is distributed in different packages for different platforms and third party systems. It can be used as a stand-alone program, which does not need a third party program for integrals and Hartree-Fock MO calculations. The stand-alone program can be installed on Unix/Linux platforms or on Microsoft Windows. The Windows version (WinVB2000) also has a simple graphic user interface. The Unix/Linux version can also be used as a plug-in module for GAMESS and Gaussian. The current release of Windows version of GAMESS (WinGAMESS) has VB2000 fully integrated and GAMESS provides an option to access VB2000 module.