Thermochemical and Theoretical Investigations of the Sodium-Oxygen System. II. Properties of NaO and Its Ions from Hartree-Fock Molecular Orbital Studies

Accurate Hartree‐Fock wavefunctions, computed by the method of Roothaan, are reported for the ²II and ²Σ states of NaO, for the ³Σ state of NaO⁺, and for the ³II, ³Σ, and ¹Σ states of NaO⁻. Spectroscopic constants and dipole and quadrupole moments have also been calculated for each of the molecules and ions. Several properties of the $\mathrm{Na}–\mathrm{O}$ species have been deduced. These properties include the vertical and adiabatic ionization potentials (7.7 and 7.4 eV), electron affinity (1.1 eV), dissociation enthalpy (2.7 eV), several thermodynamic functions for NaO, and the ${}^3{\mathrm{\Pi \; \to }}^1\Sigma$ (1.7 eV) and ${}^3{\mathrm{\Pi \; \to }}^3\Sigma$ (0.2 eV) excitation energies for the NaO⁻ system. Thermodynamic data for selected reactions involving NaO and NaO⁺ are given, together with a brief discussion of the bond enthalpies in NaO₂ and ${\mathrm{NaO}}_2^{+}.$