DIELECTRIC SCREENING, EXCITON BINDING-ENERGY AND THE INSULATOR METAL TRANSITION IN MOLECULAR-HYDROGEN

Using a model for dielectric screening in molecular hydrogen we calculate the static dielectric constant epsilon (0) in the proximity of the insulator-metal transition. The dielectric constant epsilon (0) is constructed in terms of the energy gap, the exciton binding energy and the plasmon frequency. Considering the energy gap from the band-structure calculation of Friedli and Ashcroft and making an estimate of the lower exciton binding energy in the instability region, epsilon (0) is shown to diverge at a critcal density given by r//s* equals 1. 57 a. u.