Fourier transform infrared emission spectra of MgF2

Abstract

High resolution infrared emission spectra of hot MgF$_{2}$ in the 700 to 1300 cm$^{-1}$ region have been recorded. The molecules were generated by heating solid MgF$_{2}$ to 1675 $^{\circ}$C. Four vibrational bands were rotationally analyzed yielding band origins and rotational constants. Observed bands are: 001-000 ($\Sigma$$_{u}$$^{+}$ - $\Sigma$$_{g}$$^{+}$), 01$^{1}$1 – 01$^{1}$0 ($\Pi$$_{g}$ – $\Pi$$_{u}$), 02$^{2}$1 (f parity) – 02$^{2}$0 (f parity) ($\Delta$$_{u}$ – $\Delta$$_{g}$), and 03$^{3}$1 – 03$^{3}$0 ($\Phi$$_{g}$ – $\Phi$$_{u}$). High level {\em ab initio \em} calculations were essential in making assignments and in helping to fit the data. The $\Delta$$_{u}$ – $\Delta$$_{g}$ band was only observed for f-parity because the e-parity is significantly perturbed by l-resonance.