On the Calculation of Electric Field Gradients in Layered Compounds

Abstract

An analytical formula is derived for the electric field gradient (EFG) of a thin slab with an arbitrary charge density in the - -plane without -dispersion, based on its Fourier expansion. It turns out that the EFG is dominated by the leading Fourier-coefficients for thin slabs and reduces to a contact-term proportional to the charge density at the nucleus in the truly two-dimensional case. An extension to charge density distributions which are factorizable into a function f(x,y) and g(Z) is given with an example for a Gaussian g(Z). The consequences for EFGs in layered compounds such as TaS2 and TaSe2 are discussed