Inelastic neutron scattering (INS) spectroscopy, contrary to other vibrational spectroscopic techniques such as infrared or Raman spectroscopies, provides richer microscopic insight into a material due to the absence of selection rules induced by the symmetry of the molecule 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, there is a need to include the neutron scattering cross sections, overtones and combination modes, together with instrument specific E-Q windows. Here we present abINS, which is implemented as an open source ​algorithm in Mantid. This uses the normal modes that are obtained from DFT calculations.  As the algorithm is available within Mantid, it is straightforward to compare theory and experiment.

​Following features are available in abINS available in Mantid version 6.3:

• ability to use data from a number of DFT lattice dynamics packages: CASTEP, CRYSTAL, DMOL3, GAUSSIAN, VASP, PHONOPY
  
• providing temperature adjustment through the Debye-Waller factor
  
• providing control over overtones (1 to 10)
• providing atom projected INS spectrum for in-depth analysis
• providing control over TOSCA forward and backward detectors
  

More information about abINS will be found here

INS spectra calculated using abINS in Mantid from the lattice dynamics calculations using CASTEP:

If you use abINS, please cite:

K Dymkowski, SF Parker, F Fernandez-Alonso and S Mukhopadhyay, "AbINS: The modern software for INS interpretation",​ Phys. B  551, 443 (2018). doi:10.1016/j.physb.2018.02.034

The other software for TOSCA data analysis is aClimax.