AbINS: The modern software for INS interpretation

Inelastic neutron scattering (INS) spectroscopy, contrary to other vibrational spectroscopic techniques such as infrared or Raman spectroscopies, provides much richer microscopic insight into a material due to the absence of selection rules induced by the system's symmetry and via its dependence on both energy (E) and momentum (Q) transfer. First-principles density functional theory (DFT) based calculations are now routinely used to interpret infrared and Raman spectra. These calculations can also be used to interpret INS spectra, however, the need to include the neutron scattering cross sections, overtones and combination modes, together with instrument specific E-Q windows make the data analysis challenging. Here we present AbINS: a new generation of software to interpret INS spectra using ab initio phonon data. AbINS is an open-source package implemented as a plugin to the neutron data analysis software, Mantid and offers the facility to plot the full (Q, E) map for powder samples, with the option to extract individual atomic contributions. This option is then applied to analyse the vibrational spectrum of non-hydrogenous K2SiF6 to extract atom-type contributions identifying T-1g librational mode of the [SiF6](2-) ion together with the T-2u F-Si-F bending mode.