Forces from Stochastic Density Functional Theory under Nonorthogonal Atom-Centered Basis Sets

Ben Shpiro, Marcel David Fabian, Eran Rabani, Roi Baer, Eran Rabani, Roi Baer

Research output: Contribution to journalArticlepeer-review

Abstract

We develop a formalism for calculating forces on the nuclei within the linear-scaling stochastic density functional theory (sDFT) in a nonorthogonal atom-centered basis set representation (Fabian et al. Wiley Interdiscip. Rev.: Comput. Mol. Sci. 2019, 9, e1412, 10.1002/wcms.1412) and apply it to the Tryptophan Zipper 2 (Trp-zip2) peptide solvated in water. We use an embedded-fragment approach to reduce the statistical errors (fluctuation and systematic bias), where the entire peptide is the main fragment and the remaining 425 water molecules are grouped into small fragments. We analyze the magnitude of the statistical errors in the forces and find that the systematic bias is of the order of 0.065 eV/Å (∼1.2 × 10-3Eh/a0) when 120 stochastic orbitals are used, independently of system size. This magnitude of bias is sufficiently small to ensure that the bond lengths estimated by stochastic DFT (within a Langevin molecular dynamics simulation) will deviate by less than 1% from those predicted by a deterministic calculation.

Original languageEnglish
Pages (from-to)1458-1466
Number of pages9
JournalJournal of Chemical Theory and Computation
Volume18
Issue number3
DOIs
StatePublished - 8 Mar 2022

Fingerprint

Dive into the research topics of 'Forces from Stochastic Density Functional Theory under Nonorthogonal Atom-Centered Basis Sets'. Together they form a unique fingerprint.

Cite this