Time-dependent self-consistent harmonic approximation: Anharmonic nuclear quantum dynamics and time correlation functions
Lorenzo Monacelli, Francesco Mauri
Abstract
Simulating nuclear quantum dynamics in strongly anharmonic materials is an open challenge where state-of-the-art techniques fail. This is relevant in ferroelectrics, charge density waves, and crystals encapsulating light atoms, such as superconductive high-pressure hydrides. Here, the authors develop a theory to compute dynamical properties and predict experimental Raman and IR spectroscopy, neutron scattering, and x-ray scattering of any material, accounting for the nuclear quantum and anharmonic dynamics.The method is efficient and can be applied to systems with hundreds of atoms even when treating electrons $a\phantom{\rule{0}{0ex}}b$ $i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}o$ within density functional theory.