Ab initio study of the pair potentials and electric dipole moments of the ArHe and NeHe diatoms

Abstract

Large basis set $\text{Ab}$ $\text{Initio}$ calculations are reported for the variation of energy and electric dipole moment with internuclear separation for the diatoms ArHe and NeHe. Electron correlation effects are treated explicitly by the self consistent electron pairs method, and are found to be large. The effect of basis set superposition is examined, and found to be significant. Calculated potential well depths D_e and equilibrium internuclear separation R_e compare with the ε_m and R_m values found by fitting various experimental data. The electric dipole moment p_e for the ArHe diatom at distances ≈ RI_e is larger than that for the NeHe diatom, in accordance with the fact that the full collision induced absorption spectrum has been observed experimentally only for the latter. The variation of p_e with R shows fine structure at R ≈ R_e not previously reported.