A new formula for predicting low-temperature evaporation field

An elementary formula is derived that enables the approximate prediction of the field strength for low-temperature field evaporation, using chemical thermodynamic data. The new formula closely resembles the familiar Müller–Schottky formula, but its derivation relies only on a general argument concerning energetics, and does not employ the physically dubious arguments concerning potential curves that are implicit in image-hump formalisms. It is suggested that the new formula could usefully supplant the Müller–Schottky formula in elementary discussions of field evaporation.