carlos-ccm / GFN1-xTB__TCCM_Project

TCCM's xTB code

Semiempirical GFN1-xTB Method code

Development of a coding project for the TCCM Master. The project consist of creating from scratch a code that performs semiempirical DFT calculations for a given molecule, composed by H, C, N and O.

Method based on the theory developed in “Extended tight-binding quantum chemistry methods”, C. Bannwarth, E. Caldeweyher, S. Ehlert, A. Hansen, P. Pracht, J. Seibert,S. Spicher and S. Grimme, WIREs Comput. Mol. Sci. 2021, 11 e1493, DOI: https://doi.org/10.1002/wcms.1493.

Author: Carlos Cruz Marin
Twitter: @c_cruz_TC

Table of Contents

1. Installation
2. Inputs
3. Usage
4. References

Installation

For running this code you will only need the following packages installed:

• Numpy

# Set up steps
git clone https://github.com/carlos-ccm/xtb.git
pip install numpy

Inputs

When running the code you will need to provide some inputs.

• Molecule geometry (.xyz format)
• File containing the parameters (parameters.dat)

Usage

The code includes the following flags

-help Description of the code
-i <xyz file>
-p <parameters.dat>

References

• A general overview of the GFNn-xTB methods (n = 0, 1, 2): “Extended tight-binding quantum chemistry methods”, C. Bannwarth, E. Caldeweyher, S. Ehlert, A. Hansen, P. Pracht, J. Seibert, S. Spicher and S. Grimme, WIREs Comput. Mol. Sci. 2021, 11 e1493, DOI: https://doi.org/10.1002/wcms.1493.
• Systematic description of the GFN1-xTB method and its performance: “A Robust and Accurate Tight-Binding Quantum Chemical Method for Structures, Vibrational Frequencies, and Noncovalent Interactions of Large Molecular Systems Parametrized for All spd-Block Elements (Z = 1 – 86)”, S. Grimme, C. Bannwarth and P. Shushkov, J. Chem. Theory Comput. 2017, 13, 1989 – 2009, https://doi.org/10.1021/acs.jctc.7b00118.
• Description of the DFTD3 dispersion correction: “A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-Pu”, S. Grimme, J. Antony, S. Ehrlich and H. Krieg, J. Chem. Phys., 2010, 132, 154104, https://doi.org/10.1063/1.3382344.
• Description of the ‘Becke-Johnson’ short-range dampiung function: “A post-Hartree-Fock model of intermolecular interactions: Inclusion of higher-order corrections”, E. R. Johnson and A. D. Becke, J. Chem. Phys., 2006, 124, 174104, https://doi.org/10.1063/1.2190220,andrefs.\therein..