thermocalc - a poor man's approach to computational thermochemistry

Area of Science:

• Computational chemistry
• Quantum chemistry

Background:

• Accurate calculation of molecular energies is crucial for understanding chemical reactions and properties.
• Existing methods can be computationally expensive for large molecules.

Purpose of the Study:

• To present thermocalc, an automated Perl module for calculating atomization energies and heats of formation.
• To enable efficient and accurate quantum chemical calculations for sets of molecules.

Main Methods:

• Utilizes density functional theory (DFT) and second-order perturbation theory.
• Employs a three-step protocol with TURBOMOLE: pre-optimization/zero-point energy, geometry optimization, and single-point energy calculation.
• Incorporates a user-modifiable level of theory for customized protocols.

Main Results:

• Demonstrates reasonable throughput rates for medium to large molecules.
• Developed a one-parameter correction term based on shared electron numbers.
• Significantly reduced the error in calculated heats of formation.

Conclusions:

• Thermocalc provides an efficient and accurate method for calculating thermochemical properties.
• The developed correction term enhances the reliability of computed heats of formation.
• The module offers flexibility for customized computational protocols in quantum chemistry.