d-Hybridization of the Pi Bond in the 2pπu State of H2+

LCAO—MO calculations have been made for the 2pπu state of H2+. Trial wave functions have been constructed which involve dπ orbitals as well as pπ orbitals about the two nuclei, and the energy has been computed for internuclear distances between 2 and 10 a.u. The discrepancies between these energies and the exact energies are decreased by as much as 87% as compared with the discrepancies obtained on using p orbitals alone. Inclusion of d orbitals also results in a considerable improvement in the equilibrium internuclear distance. The maximum ratio of the coefficients of the d orbitals to those of the p orbitals is about 0.24. The approximate wave functions have also been compared graphically with the exact solution.