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georginaS

Member

Registered: 2026-07-24

Posts: 1

RASSI - SOC absolute values

Hiya, I have a question about the magnitude of SOC calculated with RASSI. I want to calculate the SOC between a quartet state and a doublet (assuming this is the same as between the doublet and the quartet). The quartet state splits into its 4 corresponding microstates (1 2 3 4) and the doublet splits into its 2 correpsonding microstates ( 5 and 6).

If I wanted to obtain the magnitude of the overall SOC between the quartet and the doublet state - would I calculate the RMS between all four values of the matrix ie SQRT(64.7^2+64.7^2+37.4^2+37.4^2)=106 cm-1 or would it be just SQRT(64.7^2+37.4^2) = 75 cm-1?

Many thanks for your help

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 Complex SO-Hamiltonian matrix elements over
 spin components of spin-free eigenstates (SFS):
 (In cm-1. Print threshold:      0.000 cm-1)
 ----------------------------------------------------------------------

  I1  S1  MS1    I2  S2  MS2    Real part    Imag part      Absolute
     5  0.5 -0.5    1  1.5 -1.5       -64.731         0.000        64.731
     5  0.5 -0.5    3  1.5  0.5       -37.373        -0.000        37.373
     6  0.5  0.5    2  1.5 -0.5       -37.373         0.000        37.373
     6  0.5  0.5    4  1.5  1.5       -64.731        -0.000        64.731
 ----------------------------------------------------------------------

       Total energies including SO-coupling:
::    SO-RASSI State    1     Total energy:   -3290.75802313897611
::    SO-RASSI State    2     Total energy:   -3290.75802313897611
::    SO-RASSI State    3     Total energy:   -3290.75802154378061
::    SO-RASSI State    4     Total energy:   -3290.75802154378061
::    SO-RASSI State    5     Total energy:   -3290.68531280856132
::    SO-RASSI State    6     Total energy:   -3290.68531280856132