Dynamic quantum crystallography: lattice‐dynamical models refined against diffraction data. I. Theory. Issue 2 (26th February 2016) - Hoser, Anna A.
Abstract : A new refinement approach based on lattice dynamics derived from periodic ab initio calculations is described. The approach is tested on high‐resolution diffraction data for urea. Abstract : This study demonstrates and tests the refinement of a lattice‐dynamical model derived from periodic ab initio calculations at the Γ point against elastic diffraction data (X‐ray or neutron). Refinement of only a handful of parameters is sufficient to obtain a similar agreement with the data as the conventional crystallographic model using anisotropic displacement parameters. By refinement against X‐ray data, H displacement parameters are obtained which compare favourably with those from neutron diffraction experiments. The approach opens the door for evaluating thermodynamic properties, and for refinement against multi‐temperature data, against inelastic diffraction data, spectroscopic information and thermal diffuse scattering data.