Year: 2025
Type: preprint
Abstract: We present an extension of the shadow extended Lagrangian Born-Oppenheimer molecular dynamics (XL-BOMD) method to excited state molecular dynamics (ESMD) in the context of \DeltaSCF Kohn-Sham density functional theory, with demonstrations performed using self-consistent charge density functional tight binding (SCC-DFTB) theory. In this shadow ESMD approach, the approximate iterative solution to the exact potential in conventional ESMD is replaced by an exact single-step solution to an approximate shadow excited-state potential. We show that in addition to offering significant improvement in computational cost relative to direct ESMD, our shadow ESMD method provides enhanced stability and robustness relative to its 'exact' counterpart. Our implementation is carried out in the context of SCC-DFTB theory but should be broadly generalizable, both to {\textit{ab initio}} electronic structure methods and to other semi-empirical quantum chemistry approaches.
Source: arXiv (Cornell University)
Authors: Fajen, O. Jonathan, Grånäs, Oscar, Martínez, Todd J., Niklasson, Anders M. N.
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W6966930586