[gpaw-users] LCAO mode for Zeolite

[baldissin]

Dear gpaw users

I am calculating the site preference of Al substitution in zeolite.
Unit cells are massive ( 20x20x13 Ang ). My idea is using LCAO mode. 
I am wondering if the method is accurate enough to discriminate energy
with difference of some meV (5-20).
any opinion?

thanks a lot
Gael

PS:   calc = GPAW( mode='lcao' ,  h=0.18, nbands=-5, xc='PBE',
txt='atoms.out', kpts=[(0, 0, 0)], usesymm=True , charge=-1,
maxiter=150   )