Implementation of screened hybrid density functional for periodic systems with numerical atomic orbitals: basis...

Area of Science:

• Computational Chemistry
• Materials Science
• Quantum Mechanics

Background:

• Accurate electronic structure calculations are crucial for understanding material properties.
• Hybrid density functionals offer improved accuracy over standard approximations but are computationally expensive.
• Efficient methods are needed for large periodic systems.

Purpose of the Study:

• To present an efficient O(N) implementation of screened hybrid density functional theory (DFT) for periodic systems.
• To utilize numerical atomic orbitals (NAOs) for computational efficiency.
• To accelerate calculations through optimized integral screening.

Main Methods:

• Implementation of a screened hybrid density functional using numerical atomic orbitals (NAOs).
• Fitting valence electron NAOs with Gaussian-type orbitals for integral calculations.
• Direct construction of Hamiltonian matrix elements with NAOs.
• Adoption of strict locality of NAOs for efficient two-electron integral screening.

Main Results:

• Achieved an O(N) computational scaling for screened hybrid DFT in periodic systems.
• Demonstrated the convenience of Gaussian-fitted NAOs for Hartree-Fock exchange matrix elements.
• Successfully applied NAO locality for significant speed-up via integral screening.

Conclusions:

• The developed O(N) method provides an efficient route to screened hybrid DFT for periodic systems.
• NAOs offer a practical basis set for accurate and fast electronic structure calculations.
• This implementation facilitates larger and more complex material simulations.