“…[7] The infrared spectrum of silane, SiH 4 , was first studied in 1935 by Steward and Nielsen [8] and a set of fundamental frequencies for the most abundant isotopomer was first obtained in 1942 by Nielsen and coworkers. [9] The isotopomers of SiH 4 have been the subject of considerable high-resolution experimental work; for instance, we note [10,11] [15,16] for 28 SiHD 3 , and [17,18] for 28 SiD 4 . The molecule is of considerable astrophysical interest, having been detected spectroscopically in the atmospheres of Jupiter and Saturn [19] and in the interstellar gas cloud surrounding the carbon star IRC+10 216 [20] Until most recently, only fairly low-resolution data [21] were available for SiH 2 D 2 ; as the present paper was being prepared for publication, a high-resolution study [22] of the {ν 3 , ν 4 , ν 5 , ν 7 , ν 9 } Coriolis resonance polyad appeared, in which assignments were facilitated by mixed basis set CCSD(T) and MP2 calculations of the quartic force field.…”