Correlated Gaussian wavefunctions for H3+

Quantum chemical calculations have been performed on ${\mathrm{H}}_3^{+}$ using correlated Gaussian wavefunctions of a type suggested by Singer. The resulting upper bound energy, E = −1.34335 a.u., is lower than all previous results except those of Conroy. Vibrational frequencies were calculated to be ω₁ = 3272 cm⁻¹ (symmetrical stretch) and ω₂ = 2735 cm⁻¹ (bending mode). The kinetic energy, nuclear repulsion energy, interelectronic repulsion energy, nuclear‐electronic attraction energy, virial, and squared electronic position expectation values were computed.