Theoretical estimates of the rotational g-factor, magnetizability and electric dipole moment of GaH

The rotational g-factor, magnetizability and electric dipole moment of GaH were calculated using several perturbative and multiconfigurational polarization propagator approximations. The coupled perturbed Hartree-Fock (CHF) result for the rotational g-factor (gJ = −3.245 for 69Ga1H at the experimental equilibrium geometry) is in good agreement with a recent estimate of the rotational g-factor from non-adiabatic rotational effects observed in field-free vibration-rotation spectra of GaH. However, no agreement is found between the experimental estimate and the results of calculations including electron correlation (gJ = −3.380 at the level of the second order polarization propagator approximation with coupled-cluster singles and doubles amplitudes — SOPPA(CCSD) — and gJ = −2.946 using a multiconfigurational polarization propagator approach (MCPPA)). Averaged values of gJ for the v = 0, J = 1 and v = 1, J = 1 ro-vibrational states are reported for all isotopomers, which are less negative than the results for the equilibrium geometry. GaH is predicted to be diamagnetic. The results for the electric dipole moment are in disagreementwith the estimate from non-adiabatic rotational effects. Ro-vibrational averaging increases the absolute value of the the dipole moment.