ExSCF

ExSCF is a program for methods based on Projected Hartree-Fock.

Pre-requisites

• sympy
• PySCF
• pyAutoMR
• MOKIT (optional, for read/write fch)

Of course we need numpy, scipy, etc., but these are also required by PySCF, so they are not listed here.

Installation

(1) From pypi

pip install exscf

(2) From source

• git clone
• add /path/to/ExSCF to your PYTHONPATH

Features

Theoretical features:

• SUHF (Spin-projected Unrestricted Hartree-Fock)
  • energy
  • 1pdm, natural orbitals, 2pdm
• SU-PDFT

not fully tested, or not fully implemented yet:

• SUHF+DFT, SUHF+fDFT, SUHF+fcDFT
• CAS+fDFT, CAS-DFT2
• DeltaSCF with MOM
• PAV-SUMP2, SUMP2(0)

Technical features:

• guess
  • mix (guess.mix)
  • fragment (guess.from_frag)
  • stablize UHF (guess.check_stab)
• converging strategy
  • DIIS (diis_on = True)
  • level_shift = (in a.u.)
• interface (require MOKIT)
  • read guess MO from fch (guess.from_fch_simp)
  • dump MO, NO to fch (tofch = True)

more guess strategies are included in pyAutoMR.

Quick Start

from pyphf import suscf, guess

xyz = 'H 0.0 0.0 0.0; H 0.0 0.0 2.0'''
bas = '3-21g'
mf = guess.mix(xyz, bas, conv='tight')

mf2 = suscf.SUHF(mf)
mf2.kernel()

Contact

For bug report or comments, please contact the author via srwang20@fudan.edu.cn or open an issue.