The Hamiltonian for V(IV)-Co(II) system should be
H = J(S1S2)+ lsoc(S2L2)+mBB(gS1+gS2-L2)
where 1=V, 2=Co
and there is the isotropic exchange between spins, spin-orbit coupling between S2 and L2 and Zeeman term.
Next level is to include also CF terms for L2.
Similar system can be operable also for V(IV)-Ln(III) systems.
Is this what you asked for?
R.
Ok, that helps. The orbital Zeeman term in your Hamiltonian is negative, whereas EasySpin uses a positive sign. Try Sys.orf=-1. You might have to change the sign of the Sys.soc as well, since Sys.orf enters both the orbital Zeeman and the spin-orbit coupling terms.
In hindsight, the choice of using Sys.orf that enters two different Hamiltonian terms (orbital Zeeman and spin-orbit) might not have been ideal. My inclination, based on this thread, is to change this for the final 6.0 version: eliminate Sys.orf from the spin-orbit term, and for the Zeeman term rename it to Sys.gL or similar. The Hamiltonian would then simply be Sys.soc*S*L + muB/h*gL*B*L. What do you think about this proposal?