SOC Constants

[hherbol]

Is there a way to get Turbomole to output all the state-to-state Spin-Orbit Coupling constants when doing an X2C calculation in ESCF?  I've tried using the proper program "proper -> mos -> socme", but I get the following error:

socme
 SOCME elements may make sense with magnetic fields in soghf case
 but the needed integrals are not yet available sorry, have to stop.

========================
 internal module stack:
------------------------
    proper
    propmos
    propsocme
========================

 SOC element calculation not supported with soghf keyword
 proper ended abnormally
 proper ended abnormally
program stopped.

I assume I'm either doing something wrong, or it's just not a feature of Turbomole yet.  Does anyone know? It seems odd that it's not a feature as technically speaking Turbomole can calculate TDM vectors, which are SOC weighted sums of various ground state and excited state transitions.

[chris.hol]

Dear hherbol,

sorry for the late reply, but maybe this is interesting for others, too. It is not possible to calculate SOC constants in a 2c X2C calculation. This is not a technical limitation. In a 2c X2C calculation, SOC is included already in the orbitals, and SOC and dipole moments loosely spoken form the transition dipole moment -> which is automatically non-zero also for singlet-triplet excitations in that case.

Best regards

[hherbol]

Interesting, thanks for the reply!  In that case though, it makes it a little harder to isolate the contributions to the transition dipole moment between Singlet-Triplet excitations doesn't it?  Normally it's a perturbation of the S0->Sn and T1->Tn transitions based on the SOC contributions (scaled by relative energies).  So if I were to want to identify the largest contributors to some TDM, is it just not possible with X2C?

[chris.hol]

It's a bit harder conceptually, though the oscillator strength/transition dipole moment for a S0->T1 transition is directly calculated in a 2c escf calculation. Decomposing this into a mixture of singlets and triplets is not possible; in case you want to do something like this, you would need to start from a 1c (scalar relativistic only) calculation and do perturbation theory

[hherbol]

Thanks for the quick reply! Rarely do I see an online forum get such activity.  I guess I'll have to take the 1c slog and figure it out that way.