Molecular potential-energy surfaces by interpolation: Further refinements

Abstract

We present some refinements of a recently developed scheme for interpolating and iteratively improving molecular potential-energy surfaces (PES). By comparison with an analytic surface for the OH+H ₂ →H ₂ O+H reaction, we show that an accurate and smooth PES may be constructed using of the order of 100–200 calculations of the energy, energy gradient and second derivatives. The refinements rely, in part, on improved methods for determining the optimum locations for these calculations.