Line Shape of Ultraviolet Absorption in Solid Noble Gases

The absorption of ultraviolet radiation in solid noble gases shows lines that are a few hundred inverse centimeters broad. An attempt is made to explain and calculate the width and shape of these lines on the basis of a tentative curve of energy versus configuration. It is shown that the width has the proper order of magnitude. The line shape can be easily calculated at the short wave length end. It should show an exponential tail. If we inspect the expression for small values of the energy, we find a rapidly rising exponential, which will give rise to a smeared-out edge appearance. The line will have a nonsymmetrical shape.