Abstract
Compton scattering of 59·54 keV gamma rays in single-crystal sodium chloride along (100) and (110) directions are reported for the first time. The measured anisotropy J l00(q) — J 100(q) is found to be in close agreement with both the linear combination of atomic orbitals (LCAO) results, (i) using series orthogonalization taking two orders of neighbours into account and (ii) 'exact' orthogonalization for a cluster of 365 ions. The extrema in the measured anisotropy beyond q= 1 a.u. are slightly shifted towards lower q values as compared to theory. The measured absolute profiles are in somewhat better agreement with the LCAO theory using series orthogonalization. Auto-correlation functions for the (100) and (110) directions determined from the theoretical and experimental Compton profiles agree reasonably well with each other except for slight deviations observed for the (100) direction.