Adiabatic path integral molecular dynamics methods. I. Theory

Autor:	G. J. Martyna
Rok vydání:	1996
Předmět:	Physics Classical mechanics Normal mode Quantum dynamics Path integral molecular dynamics Path integral formulation General Physics and Astronomy Centroid Method of quantum characteristics Semiclassical physics Physical and Theoretical Chemistry Classical limit
Zdroj:	The Journal of Chemical Physics. 104:2018-2027
ISSN:	1089-7690 0021-9606
DOI:	10.1063/1.470958
Popis:	Recently, a finite temperature semiclassical quantum dynamics method based on the use of classical trajectories generated on the centroid potential of mean force, the free energy surface associated with the path integral centroid [Cao and Voth, J. Chem. Phys. 99, 10070 (1993)], was presented. It is natural to consider whether or not a similar theory can be constructed using classical trajectories generated on the true quantum mechanical potential mean force, the free energy surface associated with a single path integral bead (canonical Wigner‐type approximations). Here, Wigner schemes are derived that give the exact quantum dynamics of quadratic actions, contain the classical limit and when used as a statistical theories give the correct rate constant for a parabolic barrier. The fundamental difference between the two types theories, Wigner and centroid, is that the Wigner formalism at very least requires a set of instantaneous normal modes while the centroid method is normal mode free.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::23bf00cfb95de8c663863c0ce3138307 https://doi.org/10.1063/1.470958 Zobrazit plný text záznamu