Simulated ab initio molecular orbital technique. Part 3.—Open shell radicals in the spin unrestricted formalism

Abstract

The simulated ab initio molecular orbital (SAMO) technique, previously applied to closed-shell situations has now been applied to open-shell radicals such as the butyl radical and the pentyl radical. The odd electron here is localised in one region of the molecule. The method employs the spin-unrestricted formalism and results are compared with full ab initio calculations using the same approach. It is shown that an adequate simulation can be achieved by combining transferability of matrix elements from smaller open-shell radicals and smaller closed-shell molecules.