Infrared spectrum and potential constants of silicon tetrafluoride

Doppler‐limited tunable diode laser spectra of ν4 of 28SiF4 have been analyzed and the spectroscopic constants determined. In contrast to most earlier low‐resolution studies, the Coriolis constant ζ4, when combined with ζ3 as obtained from previous laser spectroscopy, yields a zeta sum that is within 5% of the expected harmonic value of 1/2. The band origins of 12 overtones and combinations have been obtained from Fourier‐transform spectra (0.04 cm−1 resolution), resulting in estimates of the anharmonicity constants and harmonic frequencies. From the Coriolis constants and the isotope shifts in ν3 we have redetermined the general quadratic force field of SiF4.