NiPS3 is a magnetic material. Its structure has similarities to graphite in that the atoms are strongly bound in planes but the planes are only weakly bound. It is called "quasi-two-dimensional" for this reason. Its magnetism is also quasi-two-dimensional, with strong magnetic interactions within the planes and only weak interactions between the planes. This makes it potentially very useful to test detailed theory models for magnetism in two dimensions. We wish to use neutron inelastic scattering to measure the magnetic fluctuations within the compound, to determine the strength of the intra- and interplanar interactions and thus to be able to test quantitatively the theories that describe low-dimensional magnetism.