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karney

Member

From: University of San Francisco

Registered: 2018-09-07

Posts: 4

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Oscillator strengths in RASSI

Hello,
I am running excited state calculations and trying to get oscillator strengths (f) for electronic transitions. In the RASSI output, there are TWO tables--one for "dipole transition strengths" and another for "velocity transition strengths". Which values should I use? An example of the two tables (truncated) is below.

Thanks,
William Karney

------------------------------------------------------------------------------------------------------
++ Dipole transition strengths:
   ----------------------------
    for osc. strength at least   0.10000000E-04
         To  From     Osc. strength   Einstein coefficients Ax, Ay, Az (sec-1)       Total A (sec-1)
         -------------------------------------------------------------------------------------------
         1    2       0.80318990E-02   3810714.9       7386.2110       0.0000000       3818101.1
         1    3       0.54112628E-02   4098865.4       225514.68       0.0000000       4324380.1
         1    4       0.38455699E-03   24541.885       336384.70       0.0000000       360926.58
------------------------------------------------------------------------------------------------------
++ Velocity transition strengths:
   ----------------------------
    for osc. strength at least   0.10000000E-04
         To  From     Osc. strength   Einstein coefficients Ax, Ay, Az (sec-1)       Total A (sec-1)
         -------------------------------------------------------------------------------------------
         1    2       0.12770635E-01   5952838.1       117902.66       0.0000000       6070740.8
         1    3       0.13028746E-02   995013.66       46171.177       0.0000000       1041184.8
         1    4       0.28105601E-02   2631401.7       6454.0406       0.0000000       2637855.7
------------------------------------------------------------------------------------------------------

---

William Karney
Prof. of Chemistry and Environmental Science
University of San Francisco

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,203

Re: Oscillator strengths in RASSI

They are different approximations to the oscillator strength. Just google "length velocity oscillator strength". I don't think there's a definitive answer for which one is best, that's why you get both.