Comparison of Smooth Hartree-Fock Pseudopotentials

Area of Science:

• Computational chemistry
• Quantum chemistry
• Theoretical chemistry

Background:

• Pseudopotentials simplify electronic structure calculations by replacing core electrons and the nucleus with an effective potential.
• Scalar relativistic Hartree-Fock pseudopotentials are crucial for accurate calculations involving heavy elements and large molecules.
• The Trail-Needs-Dirac-Fock (TNDF) and Burkatzki-Filippi-Dolg (BFD) are widely adopted pseudopotentials in computational chemistry.

Purpose of the Study:

• To assess and compare the accuracy of TNDF and BFD pseudopotentials.
• To evaluate their performance for a diverse set of 34 first-row molecules.
• To determine which pseudopotential set offers superior reproduction of key molecular properties.

Main Methods:

• Hartree-Fock (HF) level of theory was employed for all calculations.
• Comparison of all-electron results with pseudopotential calculations.
• Evaluation of equilibrium geometries, molecular dissociation energies, and zero-point vibrational energies.

Main Results:

• Both TNDF and BFD pseudopotentials demonstrated good accuracy in reproducing molecular properties.
• TNDF pseudopotentials showed slightly higher accuracy compared to BFD pseudopotentials.
• The differences in accuracy were observed for equilibrium geometries, dissociation energies, and vibrational energies.

Conclusions:

• TNDF pseudopotentials offer a marginal improvement in accuracy over BFD pseudopotentials for the studied first-row molecules at the HF level.
• Both pseudopotential sets are reliable for general use in computational chemistry, with TNDF being preferable for higher precision.
• The findings guide the selection of appropriate pseudopotentials for electronic structure calculations.