Crystal field effects on the inelastic neutron scattering from heavy rare earth metals in the paramagnetic phase

Expressions which arise in the interpretation of inelastic neutron scattering from hexagonal close packed rare earth metals in the paramagnetic phase are presented and discussed. It is concluded that the fourth- and sixth-order terms which occur in the Hamiltonian describing the crystal field can, in some cases, be as important as the leading second-order term.