2021/04/07 by William A. Angermeier, Angermeier, William A., Thomas G. White +1 · 1 citation
Chemistry · Physics and Astronomy · #Advanced Chemical Physics Studies #Cold Atom Physics and Bose-Einstein Condensates #Computational Physics (physics.comp-ph) #FOS: Physical sciences #Plasma Physics (physics.plasm-ph) #Spectroscopy and Laser Applications
paper · pdf · doi:10.48550/arxiv.2104.03441
openalex publication_date 2021/04/07 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28
Wave packet molecular dynamics (WPMD) has recently received a lot of\nattention as a computationally fast tool to study dynamical processes in warm\ndense matter beyond the Born-Oppenheimer approximation. These techniques,\ntypically, employ many approximations to achieve computational efficiency while\nimplementing semi-empirical scaling parameters to retain accuracy. We\ninvestigate three of the main approximations ubiquitous to WPMD: a restricted\nbasis set, approximations to exchange, and the lack of correlation. We examine\neach of these approximations in atomic and molecular hydrogen in addition to a\ndense hydrogen plasma. We find that the biggest improvement to WPMD comes from\ncombining a two Gaussian basis with a semi-empirical correction based on the\nvalence-bond wave function. A single parameter scales this correction to match\nexperimental pressures of dense hydrogen. Ultimately, we find that\nsemi-empirical scaling parameters are necessary to correct for the main\napproximations in WPMD. However, reducing the scaling parameters for more\nab-initio terms gives more accurate results and displays the underlying physics\nmore readily.\n