Ground state rotational constants of 13CD3F and 12CD3F

Abstract Ground state rotational parameters B 0 , D 0 J , and D 0 JK have been determined for 13 CD 3 F. Spectra of 12 CD 3 F taken independently in the same time period were also assigned and analyzed as a control on the 13 CD 3 F determination. The study used data from most of the 5-μm absorption bands as observed using a 5-m Littrow spectrometer. The 13 CD 3 F parameters recovered are: B 0 = 0.6708360(40) cm −1 , D J 0 = 1.1004(44) x 10 −6 cm −1 , D JK 0 = 7.292(42) x 10 −6 cm −1 where the quoted errors are 95% simultaneous confidence limits in the last digits quoted (approximately 3 standard deviations). The results are based on 412 nonzero weighted combination differences yielding a standard deviation of the regression equal to 0.00129 cm −1 .