Combining density functional theory and Monte Carlo neutron transport calculations to study the phonon density of states of UO2 up to 1675 K by inelastic neutron scattering

International audienceSignificant advances in the use of atomistic simulation techniques, such as ab initio density functional theory and the molecular dynamics method, made it possible to predictively calculate properties of materials. In parallel, low-energy neutron scattering instruments and data analysis tools available in different institutes become mature for providing high-quality data for experimental validation purposes. Despite such experimental and theoretical improvements, the accurate modeling of experimental neutron-weighted multiphonon spectra for UO 2 over a broad temperature range still remains an issue. Combining prior phonon density of states (PDOS) from density functional theory and Monte Carlo inelastic neutron scattering calculations in a Bayesian fitting procedure is a valuable alternative approach to assess the partial PDOS of uranium and oxygen in UO 2 from 294 to 1675 K for improving the comparison to experiment and exploring the first-principles calculation hypothesis