Anomalous Energy Minima Studies by Mindo/3

A previous publication¹ utilizing the INDO² and CND0/2³ semi-empirical SCF-MO techniques has shown that these methods predict anomalous minima in the potential surfaces of small molecules and molecular ions, particularly those of type 0-X-0. Two studies have bcmen published concerning the removal of such anomalous pre-dictiors. The first approach⁴ involved reparameterization of the INDO method – specifically involving the Slater exponents α, and the bonding parameters B° of carbon and oxygen – to remove the anomalous iinimum from the potential surface of C0₂. It was de-monstrated that reparameterization could be used to remove the Salse minimum in this case; but only at the expense of the other predictive qualities of INDO, or with the prediction of an unreal-istically broad energy minimum – neither of which could b e con-sidered an acceptable solution.