The intermolecular pair-potential energy functions of the inert gases

Abstract The pair potential energy functions of the inert gas molecules may now be defined with some accuracy as a result of recent advances. These are: (i) the determination of bulk properties with greater accuracy and over wider ranges of temperature, particularly where this has revealed large errors in the existing well-established data; (ii) the increased accuracy with which theoretical calculations can be made, particularly of long-range forces; (iii) the availability of new experimental data which are more directly related to the potential energy functions than are the bulk properties. The determination of high-resolution scattering cross sections and the spectroscopic detection of the vibrational levels of the inert-gas dimers have proved particularly valuable; (iv) the increasing use of data-inversion techniques to extract information about potential functions from experimental data without the need to make restrictive assumptions about their functional forms. The resulting potential functions for the inert gases are discussed.