A REEVALUATION OF THE H3-POTENTIAL

Ab initio calculations are performed for H3 to evaluate the accuracy of fitted potentials, primarily in the energy region between 23 and 33 kcal/mol above H+H2. The double many-body expansion (DMBE) of Truhlar and co-workers is found to agree with all of the ab initio points to within 1.13 kcal/mol and to have a root mean square deviation with the computed points of 0.42 kcal/mol. We also show that expansion of the one-particle basis set reduces the difference with the DMBE surface slightly. © 1990.