A GRAZING-INCIDENCE X-RAY-DIFFRACTION STUDY OF THE TRANSVERSE STRUCTURE-FUNCTION OF THE LIQUID-VAPOR INTERFACE OF GA

We report the results of a grazing incidence x-ray diffraction study of the liquid-vapor interface of Ga. It is shown that the transverse structure function in the liquid-vapor interface of Ga is indistinguishable from the structure function of bulk liquid Ga. When compared with the transverse structure functions obtained from calculations of models of the liquid-vapor interface of a similar system [J. Chem. Phys. 86, 1036 (1987)], this result implies that the widely used point local density approximation to the properties of an inhomogeneous liquid is inaccurate and must be replaced by a representation which includes, at least to first order, the effect of the force which generates the density inhomogeneity in the liquid.