Ground state rotational energies of arsine

An analysis of the ground state of arsine is performed by using all the line assignments coming from a recent investigation of the vibrational system 2 nu(2)/nu(2) + nu(4)/2 nu(4)/nu(1)/nu(3) at 1650-2350 cm(-1). A set of 6837 ground state combination differences is used, in combination with all FIR and radio-wave and microwave data (RMW) available in the literature, to refine the ground state parameters. The rotational model takes into account all the nondiagonal contributions in [K\K +/- 3] and [K\K +/- 6], which are calculated via diagonalization, as well as the hyperfine interactions. The best estimates of the ground state parameters include 12 rotational and 4 quadrupole parameters. The overall rms deviation of the fit is 0.225 MHz for 7142 data fitted. The deviations for IR, FIR, and RMW data separately, are 0.329 x 10(-3) cm(-1), 0.279 x 10(-3) cm(-1), and 0.149 MHz, compared to average experimental uncertainties estimated to 0.5 x 10(-3) cm(-1), 0.2 x 10(-3) cm(-1) and 0.211 MHz for the three kinds of data, respectively. The parameters are compared to previous results and used for a prediction of the ground state energies up to J = 20, including hyperfine structure. A list including calculated line frequencies and intensities for all the ground state rotational transitions obeying either Delta J = 1, Delta\K\ = 0, Delta F = 0, +/- 1, or Delta J = 0, Delta\K\ = 0, +/- 3, Delta F = 0, +/- 1, is also produced up to J = 20. (C) 1996 Academic Press, Inc.