  Computational tools for normal mode analysis, which are widely used in
physics and materials science problems, are designed here in a single package
called NMscatt (Normal Modes & scattering) that allows arbitrarily large
systems to be handled. The package allows inelastic neutron and X-ray
scattering observables to be calculated, allowing comparison with experimental
data produced at large scale facilities. Various simplification schemes are
presented for analysing displacement vectors, which are otherwise too
complicated to understand in very large systems.
