Structure of the Adsorbed Helium Film near Monolayer Densities

A variational wave function is constructed for the ground state of ${\mathrm{He}}^3$ and ${\mathrm{He}}^4$ films adsorbed on graphite when the density is near that of a completed monolayer. By using this wave function, the density of the completed monolayer is calculated while the exchange effects and Debye temperatures are estimated. Comparisons with experiments are made. The pair-distribution function and the corresponding structure factor and Debye-Waller parameter are predicted.