larger wigner seitz radius during relaxation in VASP?

[arwa]

Dear Mr,
I would like to ask if using larger wigner seitz radius during relaxation in VASP would still provide a correct final structure? I did first several calculations for the bulk to find wigner seitz radius that contains most of the charge in my structure without overlapping between atoms radius. I find that the relaxation time increased when I used larger wigner seitz. Now, I have two structures: one relaxed with the default wigner seitz radius and one with the one I optimize.
I am wondering which final configuration would be more accurate? I find that the choice affects the final charge distribution.
Also, can the large size of radius prevent the structure from reaching lower energy configuration?

Thanks for your help

Regards,
Arwa

[admin]

WS radius is a numerical parameter. Calculated properties are comparable only
for calculations with the same set of parameters. You cannot compare energies
obtained using different WS radii.

[arwa]

Thanks for your respond. So, starting relaxation with different wigner seitz radius i.e different input charge density, will converge at different output positions.
Generally, can I say that relaxation with the larger wigner seitz radius (as long as no overlapping) is more accurate as it consider more electrons of the system in the relaxation? Noting that, the charge in the interstitial region is not seen or considered in the smaller radius case.

Regards,
Arwa

[admin]

Yes, the relaxation with larger WS radius is more accurate.
The size of the WS radius is a compromise, which can
be used for all types of structures without the danger of
the overlap.