We present a method, based on a non-Markovian Langevin equation, to include quantum corrections to the classical dynamics of ions in a quasiharmonic system. By properly fitting the correlation function of the noise, one can vary the fluctuations in positions and momenta as a function of the vibrational frequency, and fit them so as to reproduce the quantum-mechanical behavior, with minimal a priori knowledge of the details of the system. We discuss the application of the thermostat to diamond and to ice Ih. We find that results in agreement with path-integral methods can be obtained using only a fraction of the computational effort.
|Titolo:||Nuclear quantum effects in solids using a colored-noise thermostat|
|Autori:||Ceriotti M; Bussi G; Parrinello M|
|Rivista:||PHYSICAL REVIEW LETTERS|
|Data di pubblicazione:||2009|
|Digital Object Identifier (DOI):||10.1103/PhysRevLett.103.030603|
|Appare nelle tipologie:||1.1 Journal article|