Accurate Gaussian basis sets for atomic and molecular calculations obtained from the generator coordinate method with...

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Theoretical Chemistry

Background:

• Accurate Gaussian basis sets are crucial for reliable molecular electronic structure calculations.
• Existing methods can be computationally intensive, limiting the scope of complex calculations.

Purpose of the Study:

• To develop accurate and compact Gaussian basis sets for atoms H to Ba.
• To assess the efficiency and accuracy of these basis sets in molecular calculations using the B3LYP functional.

Main Methods:

• Employed the generator coordinate Hartree-Fock (GCHF) method with polynomial expansion for discretizing Griffin-Wheeler-Hartree-Fock (GWHF) equations.
• Utilized a non-equally distributed mesh for discretization, differing from the original GCHF approach.
• Performed test calculations on diatomic molecules (N2, F2, CO, NO, HF, HCN) using the B3LYP functional.

Main Results:

• Generated accurate Gaussian basis sets with maximum error of 0.788 mHartree for atomic Hartree-Fock energies (Indium).
• Achieved total energies comparable to cc-pV5Z basis sets (1.0–2.4 mHartree difference) using fewer polarization functions.
• Demonstrated significant reduction in computational time compared to B3LYP/cc-pV5Z calculations.

Conclusions:

• The GCHF method with polynomial expansion effectively generates compact and accurate Gaussian basis sets.
• These novel basis sets offer a computationally efficient alternative for quantum chemical calculations.
• The developed basis sets show excellent agreement with established methods and experimental data.