[Wien] SP calculations for paramegnets?

[Viktor Zano]

Dear wien2k users
I'm doing DFT calculations for phases from U-Fe-X (X is a "p" atom) systems.
Usually I do non-spin-polarisation and later spin-polarization (SP) calculation. Usually I interested in crystallography aspects (optimum volume and atomic positions).
Since it is time consuming, I rarely do spin-orbit coupling.
I got the impression that while going through these steps the energy gets lower: as I see it, in simple words, spin-orbit (SO) coupling gives the lowest energy probably due to more degrees of freedom (and relatavisticly), second one is SP, and the last on-SP. 
Is it always true or its connected to the phase?
The specific phase that was explored was reported elseware "as weak parameagnetic with temperature independent". SP calculations gave me more realistic volume than non-SP. Is it a coincidence? 
Thanks again. Would like to have any response on that!!!



____________________________
Victor Y. Zenou
PhD student
Department of Materials Engineering 
BGU‎
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