An atomic distribution function for liquid sodium is developed. A simple liquid model of the quasi-solid type is assumed in which each atom is trapped by its immediate neighbors in a small spherical cell within which it is free to move about. The resulting distribution function contains three parameters which are evaluated by fitting the function to the experimental distribution curves for liquid sodium given by Trimble and Gingrich. An approximate value of the free volume of the liquid as a function of the absolute temperature is obtained. By means of the free energy equation the entropies and latent heats of fusion and vaporization for liquid sodium are calculated and compared with the observed values.

• Received 6 October 1938

DOI:https://doi.org/10.1103/PhysRev.54.1062