The Anharmonic Force Fields of Arsine, Stibine, and Bismutine

The cubic and quartic force fields of AsH₃, SbH₃, and BiH₃ are determined from ab initio calculations using effective core potentials and polarized double-zeta valence basis sets. The computed geometries, dipole moments, rotational constants, vibration-rotation interaction constants, l-doubling constants, anharmonicity constants, vibrational wavenumbers, centrifugal distortion constants, and Coriolis coupling constants are compared with the available experimental data for AsH3 and SbH3. The vibrational wavenumbers and other spectroscopic constants for the BiH3 molecule are predicted