ABINIT Discussion Forums

Dear friends,

Recently I have accomplished one study on the polarized IR spectra of a 1D system. But one problem remains: ABINIT does not export the absolute IR absorption intensity (which is outputted by programs like CASTEP and Gaussian), but only the mode-oscillator strength. I checked Prof. Gonze's theoretical paper [PRB 55, 10355 (1997)] and several other documents but failed to find out their relationship. Could you enlighten me on the conversion factor between the mode-oscillator strength (m^3/s^2) and the usual IR absorption intensity (km/mol)?

Sincerely,
Gungfu Luo

Dear friends,

The conversion factor from m^3/s^2 to km/mol is 10^-3*pi*N/(3c^2) = 7016.82, where N and c is the Avogadro's number and light speed, respectively.

References
[1] Andrew Komornicki and Richard L. Jaffe, J. Chem. Phys. 71, 2150 (1979)
[2] W.B. Person and G. Zerbi, Vibrational Intensities in Infrared and Raman spectroscopy, 1982, pp. 160-162
[3] B. Andes Hes, JR. and Lawrence J. Schaad, Chem. Rev., 86, 709 (1988)
[4] http://cmt.dur.ac.uk/sjc/thesis_prt/node64.html

Gungfu Luo