The MRChem multiresolution analysis code for molecular electronic structure calculations: performance and scaling properties

TL;DR

MRChem is a multiresolution code for molecular electronic structure calculations that uses adaptive basis functions to achieve efficient and precise results, demonstrating favorable scaling and performance compared to traditional methods.

Contribution

The paper introduces MRChem, a multiresolution analysis code that employs adaptive basis functions for efficient and scalable molecular electronic structure calculations.

Findings

MRChem can handle systems with over a thousand orbitals at the Hartree-Fock level.

The method exhibits better-than-quadratic scaling due to implicit screening from adaptivity.

Performance comparisons show MRChem is competitive with Gaussian-based software.

Abstract

MRChem is a code for molecular electronic structure calculations, based on a multiwavelet adaptive basis representation. We provide a description of our implementation strategy and several benchmark calculations. Systems comprising more than a thousand orbitals are investigated at the HF level of theory, with an emphasis on scaling properties. With our design, terms which formally scale quadratically with the system size, in effect have a better scaling because of the implicit screening introduced by the inherent adaptivity of the method: all operations are performed to the requested precision, which serves the dual purpose of minimizing the computational cost and controlling the final error precisely. Comparisons with traditional Gaussian-type orbitals based software, show that MRChem can be competitive with respect to performance.