Fermi surface and charge density waves in niobium diselenide

The Fermi energy of niobium diselenide is calculated and the result is used to compute the wave-vector dependent susceptibility χ(q). This is found to have a fairly narrow peak at a wave-vector in very good agreement with that of the periodic lattice distortion developed by the solid at low temperature and such a peak can be seen to arise from good nesting of the Fermi surface.