Comparison of theoretical methods via different ways for assessing the heat of formation of cubane

Four ways are introduced for the comparative prediction on solid phase heat of formation Delta H-f(o) (s) of cubane through different level of theories (B3LYP/6-31G(d,p), B3LYP/6-311+G(2d,2p), B3PW91/6-31G(d,p), MP2/6-31G(d,p), and G2). It is based on the heats of sublimation Delta H-sub derived from information obtained from the quantum-mechanically calculated electrostatic potential of each isolated molecule. The Delta H-sub are combined with the aforementioned gas phase heats of formation Delta H-f(o) (g) to produce condensed phase heats of formation Delta H-f(o) (s). Comparisons of the methods are given, along with the recommendations about the methods that could produce better agreement with experiment, wishing to offer some beneficial references.