Coenzyme Q(10) (CoQ(10)) and its reduced form, ubiquinol (CoQ(10)H(2)) were
subjected to semiempirical quantum chemical treatment at the level of AM1-
RHF type calculations. Both of the structures are stable having negative to
tal and binding energies and exothermic heats of formation. The frontier mo
lecular orbital characteristics, electrostatic contour diagrams and charge
distributions of these structures were presented.