Single-Center Calculations on the Lowest-Lying Πu and Πg Excited States of H2

Abstract

Single‐center wavefunctions are constructed for the lowest‐lying singlet and triplet Π_u(1sσ2pπ) and Π_g(1sσ3dπ) excited states of the hydrogen molecule using a basis set of integral Slater‐type orbitals centered at the molecular midpoint. It is found that the convergence is more rapid than for a corresponding single‐center calculation on the ground state. The error in the binding energy is about 0.065 eV for the Π_u states and 0.033 eV for the Π_g states if a 19‐term configuration‐interaction wavefunction is used for the description of each.