[QE-users] Anisotropic exchange calculation

[Dorye Esteras Cordoba]

Dear community,

I am interested in calculating the CrBr3 J exchange parameters of an anisotropic Heisenberg Hamiltonian as it is shown in this paper: 
https://doi.org/10.1039/C2DT31662E (Equations A16 and A17 on section D in the appendix)
 My idea would be to perform a collinear spin-polarized scf calculation (i.e. using scalar relativistic pseudopotentials), and then perform a non collinear nscf calculation for each of the spin configurations, following a similar procedure as in the MAE example https://gitlab.com/QEF/q-e/-/tree/f184591e9f34cfcc7767505a23977a92286e8ba6/PP/examples/ForceTheorem_example
Would this be reasonable or should I do a non collinear scf calculation for each scenario and extract Jxx,Jyy,Jzz from the total energies? Has someone experience with this kind of calculations?

Thank you in advance
Dorye L. Esteras 
Predoctoral researcher
University of Valencia