Temperature echoes revisited to probe the vibrational behavior of dendrimers
1Centro de Química Estrutural-Complexo I, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisboa, Portugal. pedro.m.paulo@ist.utl.pt
Abstract:
Temperature quench echoes were induced in molecular dynamics simulations of dendrimers. This phenomenon was used to probe the vibrational behavior of these molecules by comparing simulation results with harmonic model predictions. The echo depth for short time intervals between temperature quenches is well described by the harmonic approximation and the fluctuations observed are related to the vibrational density of states. The echo depth for long time intervals decays progressively revealing dephasing due to anharmonic interactions. The density of states was calculated from the temperature fluctuations after the first quench and high-frequency modes were assigned by comparison with vibrational spectra of similar dendrimers.
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