The Normal State of Helium

An approximate wave function for normal helium is calculated, by using theoretically determined functions for the limiting cases of large and small r's and interpolating between them. The charge density computed from this wave function is in good agreement with that found independently by Hartree. The diamagnetism of normal helium is calculated, and agrees with observation within the experimental error. The repulsive forces between two helium atoms are calculated by the method of Heitler and London, and the attractive Van der Waals forces are roughly estimated from Wang's results with hydrogen. The potential curve so found gives a "molecular diameter" in agreement with experiment, and the minimum of the curve leads to approximately correct density and boiling point for the liquid.