Norm-conserving pseudopotentials with chemical accuracy compared to all-electron calculations

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Materials Science

Background:

• Dual space Gaussian type pseudopotentials are established methods.
• The Perdew-Burke-Ernzerhof (PBE) functional is widely used in density functional theory.
• Accurate electronic structure calculations are crucial for predicting molecular and material properties.

Purpose of the Study:

• To develop improved pseudopotentials by incorporating a nonlinear core correction.
• To enhance the accuracy of pseudopotentials for the PBE functional.
• To evaluate the performance of these new pseudopotentials for various chemical systems.

Main Methods:

• Nonlinear core correction was added to existing dual space Gaussian type pseudopotentials.
• Pseudopotentials were developed for chemical elements up to the third period.
• Benchmarks were performed using the G2-1 test set and for crystalline solids under high pressure.
• Empirical dispersion corrections were applied for molecular interaction energy calculations.

Main Results:

• The improved pseudopotentials exhibit excellent accuracy, with average atomization energy errors of approximately 0.5 kcal/mol.
• The pseudopotentials demonstrate high reliability for high-pressure phases of crystalline solids.
• With empirical dispersion corrections, the average error in molecular interaction energies is also around 0.5 kcal/mol.
• The accuracy achieved is superior to commonly used medium-sized Gaussian basis sets in all-electron calculations.

Conclusions:

• The developed nonlinear core-corrected pseudopotentials offer a significant improvement in accuracy for PBE functional calculations.
• These pseudopotentials provide a reliable and accurate approach for studying molecular and solid-state properties.
• The enhanced accuracy makes these pseudopotentials a valuable tool for computational chemistry research.