Fast and accurate quantum Monte Carlo for molecular crystals

TL;DR

This paper demonstrates that diffusion quantum Monte Carlo (DMC) can accurately and efficiently predict properties of molecular crystals, surpassing traditional methods in both precision and computational cost.

Contribution

The study shows that DMC achieves sub-chemical accuracy for molecular crystals with moderate computational effort, enabling broader application in materials science.

Findings

DMC delivers sub-chemical accuracy for molecular crystals.

DMC operates at a surprisingly moderate computational cost.

DMC can handle large molecules beyond other high-accuracy methods.

Abstract

Computer simulation plays a central role in modern day materials science. The utility of a given computational approach depends largely on the balance it provides between accuracy and computational cost. Molecular crystals are a class of materials of great technological importance which are challenging for even the most sophisticated \emph{ab initio} electronic structure theories to accurately describe. This is partly because they are held together by a balance of weak intermolecular forces but also because the primitive cells of molecular crystals are often substantially larger than those of atomic solids. Here, we demonstrate that diffusion quantum Monte Carlo (DMC) delivers sub-chemical accuracy for a diverse set of molecular crystals at a surprisingly moderate computational cost. As such, we anticipate that DMC can play an important role in understanding and predicting the properties of a large number of molecular crystals, including those built from relatively large molecules which are far beyond reach of other high accuracy methods.