An analysis of the ground state of arsine is performed by using all th
e line assignments coming from a recent investigation of the vibration
al 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 comb
ination with all FIR and radio-wave and microwave data (RMW) available
in the literature, to refine the ground state parameters. The rotatio
nal 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 s
tate parameters include 12 rotational and 4 quadrupole parameters. The
overall rms deviation of the fit is 0.225 MHz for 7142 data fitted. T
he 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 exp
erimental 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 p
arameters are compared to previous results and used for a prediction o
f the ground state energies up to J = 20, including hyperfine structur
e. A list including calculated line frequencies and intensities for al
l 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.