Basis Set Effect on Linear Response Density Functional Theory Calculations on Periodic Systems.

Area of Science:

• Computational Chemistry
• Materials Science
• Quantum Chemistry

Background:

• Accurate calculation of electronic properties for extended systems is vital in materials science.
• Density Functional Theory with Periodic Boundary Conditions (DFT-PBC) is a powerful tool for such calculations.
• The choice of basis set significantly impacts the accuracy of these calculations.

Purpose of the Study:

• To investigate the influence of basis set size on linear response (LR) calculations of electronic properties.
• To evaluate the necessity of large basis sets and diffuse functions for DFT-PBC.
• To assess the impact on properties like polarizability, optical rotation, and excitation energies.

Main Methods:

• Employed Gaussian-type atomic orbital (GTO) bases from the Dunning series (cc-pVXZ and aug-cc-pVXZ).
• Utilized an extended coupled-perturbed Kohn-Sham code within GAUSSIAN software for DFT-PBC calculations.
• Calculated electric dipole-electric dipole polarizability, optical rotation, and electronic excitation energies for 1D and 3D periodic systems.

Main Results:

• Larger basis sets, including those with diffuse functions, are essential for quantitative accuracy.
• Basis set size significantly affects LR properties in extended systems.
• Agreement with experimental data and the complete basis set limit requires extensive basis sets.

Conclusions:

• Large basis sets, augmented with diffuse functions, are indispensable for reliable LR property calculations in DFT-PBC.
• The findings underscore the importance of basis set convergence for electronic property predictions.
• This study provides critical insights for computational chemists performing electronic structure calculations on periodic systems.