Potential-hypersurface local minima and temperature

Summary The presence of several local energy minima on a potential hypersurface is treated in terms of geometry, energy, and harmonic vibrations. Partition functions of the minima are employed in order to treat temperature excitations of rotational-vibrational motions. Proportions of relative stabilities of the individual structures change with temperature (including interchanges of the relative stabilities so that the global energy minimum can even be less populated than a higher local energy minimum). Illustrative examples are given on B₂H₄ and Ga₂H₄ systems. The treatment is suggested as a standard complement of the local-minimum hypersurface representation (before whole potential hypersurfaces are constructed and employed in molecular dynamics treatments).Dedicated to Prof. Klaus Ruedenberg on the occasion of his 70th birthday