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Title: Polaron dynamics with a multitude of Davydov D{sub 2} trial states

We propose an extension to the Davydov D{sub 2} Ansatz in the dynamics study of the Holstein molecular crystal model with diagonal and off-diagonal exciton-phonon coupling using the Dirac-Frenkel time-dependent variational principle. The new trial state by the name of the “multi-D{sub 2} Ansatz” is a linear combination of Davydov D{sub 2} trial states, and its validity is carefully examined by quantifying how faithfully it follows the Schrödinger equation. Considerable improvements in accuracy have been demonstrated in comparison with the usual Davydov trial states, i.e., the single D{sub 1} and D{sub 2} Ansätze. With an increase in the number of the Davydov D{sub 2} trial states in the multi-D{sub 2} Ansatz, deviation from the exact Schrödinger dynamics is gradually diminished, leading to a numerically exact solution to the Schrödinger equation.
Authors:
 [1] ;  [2] ; ; ;  [1] ;  [1] ;  [3]
  1. Division of Materials Science, Nanyang Technological University, Singapore 639798 (Singapore)
  2. (China)
  3. (United States)
Publication Date:
OSTI Identifier:
22490865
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 143; Journal Issue: 1; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 97 MATHEMATICAL METHODS AND COMPUTING; ACCURACY; COMPARATIVE EVALUATIONS; COUPLING; EXACT SOLUTIONS; MOLECULAR CRYSTALS; PHONONS; SCHROEDINGER EQUATION; TIME DEPENDENCE