Theoretical studies of chemical reactions: potential surfaces

Calculations on the addition reaction of two hydroxyl radicals forming hydrogen peroxide are presented. An analytic representation of the long range surface was obtained by fitting the energies of 1000 points to a potential involving approximately 500 terms. The analytic potential covers the region of the potential surface from an O-O separation of 2.5 A out to two isolated OH radicals. This connects regions where electrostatic, hydrogen bonding and covalent bonding forces each, in turn, dominant the potential and will allow the detailed modeling of the addition reaction in a much more realistic manner than has here-to-fore been possible.