##master-page:HelpTemplate
##master-date:Unknown-Date
#format wiki
#language en
#Please change following line to BDF module name

= Xi'an-CI =
<<TableOfContents(4)>>

{{{
   Xi’an-CI program generates Multi Reference SDCI (MRCISD) wavefunctions (including internal contracted MRCISD on several different level accuracy), Multi Reference Second Order Perturbation Theory (including multi-state NEVPT2 (MS-NEVPT2), Multi Reference Third Order Perturbation Theory (SS-NEVPT3), Static-Dynamic-Static Second Order Perturbation Theory (SDSPT2), Static-Dynamic-Static Configuration Interaction (SDSCI), Configuration Based Multi Reference Second Order Perturbation Theory (CB-MRPT2) and Configuration Based Multi Reference Third Order Perturbation Theory (CB-MRPT3). This program is based on hole-particle symmetry based and GUGA for the computation of CI matrix elements. The program can calculate several eigenvectors simultaneously.
   Xi’an-CI program is written by Zhenyi Wen, Yubin Wang, Zhengting Gan, Bingbing Suo and Yibo Lei (Institute of Modern Physics, Northwest University, China). 
}}}
== General keywords ==
=== nroot ===
{{{#!wiki
  State Number
}}}
Example:

=== Electrons ===
{{{#!wiki
  CI effective electron Number without electrons of frozen MOs in traint module for MO integral transformation
}}}
Example:

=== Symmetry ===
{{{#!wiki
  Symmetry of the target state.
}}}
Example:

=== Spin ===
{{{#!wiki
  Spin multiplicity. 2S+1
}}}

=== core ===
{{{#!wiki
  Number of frozen orbitals in each irreps, which must be missing if it has frozen MOs in traint module.
}}}
Example:

=== Inactive ===
{{{#!wiki
  Number of inactive orbitals in each irreps.
}}}
Example:

=== Active ===
{{{#!wiki
  Number of active orbitals in each irreps.
}}}
Example: