• Document: A Practical Guide for XMVB Calculations. Peifeng Su Xiamen University
  • Size: 928.76 KB
  • Uploaded: 2019-07-20 18:12:31
  • Status: Successfully converted


Some snippets from your converted document:

A Practical Guide for XMVB Calculations Peifeng Su Xiamen University Outline  General introduction  How to write input files?  How to get information from output files? General introduction An Ab Initio Non-orthogonal Valence Bond Program Version 2.1 Lingchun Song, Zhenhua Chen, Fuming Ying, Jinshuai Song, Xun Chen, Peifeng Su, Yirong Mo, Qianer Zhang, Wei Wu* State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and Department of Chemistry, Xiamen University, Xiamen, Fujian 361005, CHINA Distributions of XMVB 2.1 Module distribution A module embedded in GAMESS-US Stand-alone distribution A stand-alone program How to Run An XMVB Job? For Stand-alone distribution (1) preint ***.inp Get integrals for VB calculation (2) XMVB ***.xmi VB calculation ***.xmo ***.orb ***.den Useful documents XMVB manual http://www.xmvb.org/art.php?id=8 Online Tutorials http://www.xmvb.org/art.php?id=4 How to write input files? How to write INT File RHF cc-pvdz HF Method; basis set 01 Charge; multiplicity H 0.000000 0.000000 0.000000 Molecular coordinates H 0.000000 0.000000 0.740000 Structure of XMI File $ORB $AIM $BFI $CTRL $GUS $FRAG $STR Optional Necessary Example 1. H2 molecule $ctrl nstr=3 iscf=5 nao=2 nae=2 orbtyp=hao frgtyp=sao $end $str 12 11 22 $end $frag 11 spz 1 spz 2 $end $orb 11 1 2 $end $ctrl iscf : orbital optimization algorithm nstr=3 iscf=5 nao=2 nae=2 (VBSCF, BOVB) orbtyp=hao frgtyp=sao When iscf=5, the two keywords are $end necessary $str nao: number of active orbitals nae: number of active electrons 12 11 iscf Gradient Performance Required keywords 22 1 Numerical Stable, slow $end 2 Analytical Fast $frag 3 Numerical Stable, slow 11 4 Numerical Stable, very slow 5 Analytical Very Fast nao, nae spz 1 6 Full Hessian Slow nao, nae spz 2 $end $orb 11 1 2 $end nstr =3, the number of structures $str : describing VB structure or $ctrl determinant. In $str, a typical structure is written as: nstr=3 iscf=5 nao=2 nae=2 orbtyp=hao frgtyp=sao $end aabbcc…mn $str 12 a b c : double occupied orbitals (inactive) 11 m n : single occupied orbitals (active) 22 $end H H 12 covalent $frag H H 11 ionic 11 22 ionic H H spz 1 spz 2 $end $orb 11 1 2 $end $ctrl orbtyp=hao, nstr=3 iscf=5 nao=2 nae=2 Hybrid atomic orbitals. orbtyp=hao frgtyp=sao localized non-orthogonal orbitals $end $str 12 11 22 $end $frag 11 spz 1 spz 2 $end $orb 11 1 2 $end How to define orbitals? Orbital Orbital Orbital Fragment Fragment Fragment Fragment Primitive basis functions Fragments are a series of basis function sets. $ctrl nstr=3 iscf=5 nao=2 nae=2 frgtyp=sao, fragments are defined with orbtyp=hao frgtyp=sao symmetrized atomic orbitals. $end $str MO Basis functions 12 11 1 22 1 H 1 S 0.317976 1 H 1 S 2 H 1 S 0.275854 2 H 1 S orb 1 $end 3 H 1 X 0.000000 3 H 1 X Frag 1 $frag 4 H 1 Y 0.000000 4 H 1 Y 11 5 H 1 Z 0.018271 5 H 1 Z spz 1 6 H 2 S 0.317976 6 H 2 S 7 H 2 S 0.275854 7 H 2 S spz 2 8 H 2 X 0.000000 8 H 2 X Frag 2 orb 2 $end 9 H 2 Y 0.000000 9 H 2 Y $orb 10 H 2 Z -0.018271 10 H 2 Z 11 1 2 $end $ctrl nstr=3 iscf=5 nao=2 nae=2 orbtyp=hao frgtyp=sao $end $str 12 11 22 $frag: description for fragments

Recently converted files (publicly available):