Electron density in KCl and LiF crystals in the self-consistent local-density-functional approximation (LDA)

The γ-ray single-crystal structure factors of Schmidt, Colella & Yoder-Short [Acta Cryst. (1985), A41, 171-175] for the 'isoelectronic' salt KCl are shown to be in excellent agreement with the values computed by us using the method of augmented spherical waves in the LDA approximation. Small differences exist for the 600 and 400 reflections whose structure factors indicate some 'asphericity' in the valence charge density - an effect not included in the theoretical calculation. The corresponding data by the same authors for the ('non-isoelectronic') salt LiF are also in good agreement with the LDA theoretical values available in the literature. A discrepancy remains, instead, between the γ-ray structure factors for 'isoelectronic' NaF by Yoder & Colella [Phys. Rev. B. (1982), 25, 2545-2549] and the LDA theoretical values.