Scatter: A New Inelastic Neutron Scattering Simulation Subroutine for GULP

Abstract

The General Utility Lattice Program [1] (or GULP, to its friends) is a well-established and popular simulation program combining the functionality of both lattice and molecular dynamics. GULP's functionality is broad, with intrinsic functions enabling the materials researcher to model the lattice and molecular dynamics of a large range of semi-empirical potential models as well as structure optimizations, defect calculations, and structure/potential fitting using standard or genetic algorithm-based approaches. Further functionality has been added recently, with a collaboration between the University of Salford's Institute for Materials Research (Salford, U.K.) and Curtin University of Technology's Nanochemistry Research Institute (Perth, Western Australia), in the development of a new inelastic neutron scattering subroutine called “scatter,” which calculates inelastic (both coherent and incoherent) S(Q,ω) data sets for lattice models within GULP, which can be averaged over crystal orientation (the polycrystalline average). These data sets can then be used to assist in the analysis of experimental data on a wide range of neutron inelastic instruments, especially when studying polycrystalline materials.

Acknowledgments

The authors wish to acknowledge the kind involvement of Drs. Stewart Parker and Steve Bennington of the ISIS facility, RAL, U.K., for access to experimental data, and John Tomkinson (ISIS) and Dr. Ian Morrison of the IMR-Salford, with assistance with issues arising during the development of the software.