Mathematical and Computational Methods in Quantum Chemistry

Adaptively compressed exchange operator

Lin Lin

University of California, Berkeley

The Fock exchange operator plays a central role in modern quantum chemistry, such as in Hartree-Fock calculations and Kohn-Sham density functional theory calculations with hybrid exchange-correlation functionals. We develop the adaptively compressed exchange operator formulation, which greatly reduces the computational cost associated with the Fock exchange operator without loss of accuracy. The ACE formulation does not depend on the size of the band gap, and thus can be applied to insulating, semiconducting as well as metallic systems. Numerical results indicate that the ACE formulation can become advantageous even for small systems with tens of atoms.