Analysis of high resolution Fourier-transform spectra (resolution 0.0024 cm-1) of .nu.2 and .nu.3 fundamental bands of D3SiF.Detection of perturbation-allowed transitions enabling a precise determination of vibrational ground state constants A 0 and DK 0 .Quantitative reproduction of all measured data with an effective rovibrational Hamiltionian in two reductions suggested by theory.