Calculation of the Geometrical Structure of Some AH Molecules

Approximate Hartree-Fock calculations for H₃, CH₂, NH₂, H₂O, H₂O⁺, BH₄ ^-, NH₄ ⁺, and CH₄ have been used to determine equilibrium angles and internuclear separations. The results are in good agreement with the experimental values where these exist. Data from these calculations are used to test the usefulness of a partition into one-electron type terms. It is found that the partitioned energies reflect the influence of the other orbitals in such a way as to render a simple interpretation very difficult. For example, the present results predict an equilibrium angle of 119° for H₂O⁺ which is very unexpected if the usual picture of a nonbonding b ₁ orbital is accepted.