标题：Finite-Temperature Single Molecule Vibrational Dynamics from Combined Density Functional Tight Binding Extended Lagrangian Dynamics Simulations and Time Series Analysis
摘要：Combining a computationally efficient and affordable molecular dynamicsapproach, based on atom-centered density matrix propagation scheme, with thedensity functional tight binding semiempirical quantum mechanics, we study thevibrational dynamics of a single molecule at series of finite temperatures, spanningquite wide range. Data generated by molecular dynamics simulations are furtheranalyzed and processed using time series analytic methods, based on correlationfunctions formalism, leading to both vibrational density of states spectra and infraredabsorption spectra at finite temperatures. The temperature-induced dynamics instructural intramolecular parameters is correlated to the observed changes in thespectral regions relevant to molecular detection. In particular, we consider a casewhen an intramolecular X-H stretching vibrational states are notably dependent onthe intramolecular torsional degree of freedom, the dynamics of which is, on the otherhand, strongly temperature-dependent.
关键词：Atom-centered density matrix propagation; density functional tight binding; molecular dynamics; finite-temperature vibrational dynamics; formic acid;torsional motion.
