Double-hybrid density functionals for the condensed phase: Gradients, stress tensor, and auxiliary-density matrix...

Area of Science:

• Computational Chemistry
• Materials Science
• Quantum Mechanics

Background:

• Double-hybrid density functionals (DHDFs) offer high accuracy for electronic structure calculations.
• Previous DHDF implementations faced high computational costs and lacked efficient gradient methods for condensed phase and periodic systems.

Purpose of the Study:

• To develop and implement an efficient method for calculating forces and stress tensors for DHDFs in periodic systems.
• To enable accurate electronic structure calculations for condensed phase materials using DHDFs.

Main Methods:

• Implementation of forces and stress tensors for DHDFs within the Gaussian and plane-waves (GPW) framework.
• Utilized the auxiliary density matrix (ADM) method to reduce the computational overhead of the Hartree-Fock (HF) kernel.

Main Results:

• Demonstrated an efficient and accurate methodology for tackling condensed phase systems using DHDFs.
• Successful application to water systems of varying densities and molecular crystals, showcasing implementation efficiency.
• Presented large benchmark systems to evaluate performance on modern high-performance computing architectures.

Conclusions:

• The developed implementation significantly enhances the applicability of DHDFs for condensed phase and periodic systems.
• This methodology paves the way for advanced computational studies of materials and molecular systems.
• The approach is efficient and scalable for large-scale computations on modern hardware.