A modified Cashion–Herschbach potential for the H3 potential energy surface

The H3 potential energy surface has been calculated using the Cashion–Hershbach (CH) potential which contains all orders of two-body Coulomb, exchange, and overlap terms. For collinear configurations, the dominant three-body contribution comes from the Axilrod–Teller–Muto triple–dipole dispersion energy. By adding only this term, properly damped, the saddle point region potential agrees with recent ab initio calculations to within 9×10−5 a.u. (0.06 kcal/mole).