A Tutorial on XMVB

Xiamen Valence Bond (XMVB) is a quantum electronic structure software focusing on ab initio nonorthogonal valence bond (VB) computation. Various ab initio VB methods are implemented in the XMVB package, including “classical” VB methods such as VBSCF, BOVB, VBCI and VBPT2, “modern” VB methods such as SCGVB, as well as molecular orbital-based BLW method. In this chapter, a tutorial on XMVB, explaining step-by-step how to run an ab initio VB calculation, will be provided. The chapter starts with information on how to install the XMVB package and how to configure the computing environment. This is followed by a brief description of the structure and content of the input and output files. Finally, seven illustrative examples are provided with more detailed practical guidelines. These examples involve the calculations of bonding energies, resonance energies, energy gaps and reaction barriers, all of which are important quantities of interest in theoretical/quantum chemistry.