Local mode spectroscopic study of the AsH3, molecule: The perturbed (500) local mode overtone

The high resolution Fourier transform spectra of AsH3 in the region of 9720 -9900 cm(-1), which had been recorded at a resolution of 0.015 cm(-1), were assigned to the (500; A(1)) and (500; E) local mode overtones and rotation ally analyzed. The effective spectroscopic parameters were obtained by nonl inear least-squares fitting the vibration-rotational Hamiltonian with the r otational energy levels up to J = 6 (98 levels in all) included. The evolut ion of the rotational energy patterns from v = 1 to v = 6 shows that the te ndency of normal mode to local mode vibration evolution has been stopped by perturbations in relatively high energy region.