GauChkParser 0.1.21

A parser for Gaussian .chk format

A parser for reading Gaussian .chk binary file

Introduction

The Python module extracts common basic information from Gaussian .chk binary file (Must generated by Gaussian x64 version, g09/g16 is OK), facilitating more efficient direct processing in subsequent steps. It does NOT rely on external tools (e.g., formchk).

Features

• Basic atomic information, such as element names, coordinates

• Hessian matrix (3N*3N symmetric matrix)

• Orbital Energies. MO coefficients

• The Shell types, The number of primitives per shell, Contraction coefficients, Primitive exponents, etc.

• write gjf, fchk file

• Total/Spin Density matrix if it exists

• TODO ...

NOTE

ONIOM is currently not supported

Installation

pip install GauChkParser

Python API

Full API documents https://gauchkparserdoc.readthedocs.io/en/latest/index.html

Example

First import GauChkParser module

from GauChkParser import ChkReader

Use ChkReader class to read your Gaussian .chk binary file

obj = ChkReader("yourjob.chk")
mol = obj.params.mol

print(f'Route: {obj.params.route}')
print(f'Natoms: {mol.natoms}')
print(f'Total charge: {mol.totchg}')
print(f'Multiplicity {mol.multiplicity}')
print(f'Element names: {mol.names}')
print(f'Coords (Angstrom): {mol.coords}')
print(f'Hessian Matrix: {mol.hessian}')
print(f'Cell size: {mol.cell}')

# write gjf file
obj.write_gjf("XXX.gjf")