Recent developments of the RMCPOW method for structural modelling

RMCPOW is a program for modelling both lattice and magnetic disorders in po wder crystalline materials by direct calculation of the structure factor, i ncluding diffuse scattering, and comparison with experimental neutron diffr action data. Here, we report recent developments, including (a) the ability to combine neutron and X-ray diffraction data, (b) the ability to use mult iple spin types, and (c) the ability to directly swap atoms which can subst itute onto the same crystallographic site. We also report the first applica tions of RMCPOW to ab initio modelling of magnetic structures. (C) 2000 Els evier Science B.V. All rights reserved.