A test for electron transfer in V4Al23

Abstract

Three-dimensional intensity data were collected from a spherical crystal of V/sub 4/Al/sub 23/ by the moving crystal-stationary counter technique. Corrections were made for the effects of absorption, dispersion, extinction, and anisotropic thermal motion of the atoms. The crystal structure was refined by the method of least squares and by difference syntheses to a reliability index of 0.057. The intensity data were placed on an absolute scale using only those reflections for which (sin theta )/ lambda > 0.29 A/sup -1/ and which are relatively insensitive to the distribution of the outer electrons. Difference syntheses were then computed for the reflections (sin theta )/ lambda < 0.29 A/ sup -1/ which are most sensitive to the distribution of the outer electrons. These difference syntheses are a measure of the difference between the equlibrium electron distribution in the crystal and that in the isolated free atoms. The results do not indicate a significantly increased electron concentration in the vanadium d levels as proposed by Raynor. (auth)