Arsenic monofluoride (AsF, 3Σ): Dissociation enthalpy, ionization potential, electron affinity, dipole moment, spectroscopic constants, and ideal gas thermodynamic functions from a Hartree-Fock molecular orbital investigation

Accurate Hartree‐Fock wavefunctions were computed by the matrix expansion method of Roothaan for the ground state (³Σ) of AsF at several internuclear separations. The equilibrium internuclear separation (r_e) was deduced to be 1.72 Å based on a Dunham analysis. It is concluded that the most probable value for $D_0^{\mathrm{o}}$ (AsF) is 4.2 ± 0.2 eV. The vertical ionization potential and electron affinity are 9.4 ± 0.2 and and 1.1 eV, respectively. It is believed that the computed electric dipole moment is too large, and an amended value of 1.75 D is recommended, with the negative end of the dipole at the fluorine atom. At r_e, the quadrupole moment measured from the center of mass is −2.44 × 10⁻²⁶ esu · cm²; however, the reliability of this result is uncertain. Ideal gas thermodynamic functions have been calculated for the temperature range 0–1000°K, based on the formulas of statistical mechanics. Koopmans' theorem yields 18.1 eV for the second ionization potential. A brief discussion of the bond enthalpies of AsF⁺, AsF²⁺, and AsF⁻ is also included. Estimates have been made of the first and second ionization potentials of SbF (8.4 and 16.3 eV) and BiF (7.3 and 16.6 eV).