Atalar, K; Rath, Y; Crespo-Otero, R; Booth, G H (2024) Fast and accurate nonadiabatic molecular dynamics enabled through variational interpolation of correlated electron wavefunctions. Faraday Discussions, 254. pp. 542-569.

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Abstract

We build on the concept of eigenvector continuation to develop an efficient multi-state method for the rigorous and smooth interpolation of a small training set of many-body wave-functions through chemical space at mean-field cost. The inferred states are represented as variationally optimal linear combinations of the training states transferred between the many-body basis of different nuclear geometries. We show that analytic multi-state forces and nonadiabatic couplings from the model enable application to nonadiabatic molecular dynamics, developing an active learning scheme to ensure a compact and systematically improvable training set. This culminates in application to the nonadiabatic molecular dynamics of a photoexcited 28-atom hydrogen chain, with surprising complexity in the resulting nuclear motion. With just 22 DMRG calculations of training states from the low-energy correlated electronic structure at different geometries, we infer the multi-state energies, forces and nonadiabatic coupling vectors at 12,000 geometries with provable convergence to high accuracy along an ensemble of molecular trajectories, which would not be feasible with a brute force approach. This opens up a route to bridge the timescales between accurate single-point correlated electronic structure methods and timescales of relevance for photo-induced molecular dynamics.

Item Type:	Article
Subjects:	Mathematics and Scientific Computing > Numerical Computation
Divisions:	Quantum Technologies
Identification number/DOI:	10.1039/D4FD00062E
Last Modified:	26 Feb 2025 10:27
URI:	https://eprintspublications.npl.co.uk/id/eprint/10026