Theoretical study of interaction potential and pressure broadening of spectral lines for the He-CH3F complex

Pressure-broadening coefficients of spectral lines of CH3F in a helium bath are evaluated by solving the close-coupling equations for the J=0-1, K=0 transition of CH3F. For that, the energy surface of the interaction potential of the CH3F-He complex has been calculated ab initio with the symmetry-adapted perturbation theory (SAPT), with CH3F kept rigid. A global 3D fit on the ab initio points in Jacobi coordinates have been done for the dynamics. Good agreement is observed between present pressure broadening coefficients and experimental data of De Lucia and collaborators.