The nu(2)/nu(4) diad of phosphine has been investigated between 920 an
d 1080 cm(-1) by laser sideband spectroscopy. Using 62 observed lines
and more than 250 transitions measured by other authors, including mic
rowave, far infrared, and laser Stark observations, a fit was performe
d, which achieved a standard deviation of 1.2 MHz. A(1)/A(2) splitting
due to vibrational rotational interaction could be resolved in ten tr
ansitions. (C) 1997 Academic Press, Inc.