[gpaw-users] Cu2O dipole corrections - convergence problems

[Isabela Man]

Dear all,
I am trying to do some calculations on different Cu2O surfaces (100, 110,
111 surfaces and for each different surface terminations).
For all cases I encounter the same problem. When I do not apply dipole
corrections , everything is fine and I get the convergence. When I apply
it, depending on surface after none, one or two steps the energy become
positive.

mixer=Mixer(0.1, 5, weight=100.0)
calc = GPAW(h=0.2,
                     xc='RPBE',
                     txt=outid,
                     kpts=(2,2,1),
                     #eigensolver='cg',
                     width=0.10,
                    #verbose=True,
                    mixer=mixer,
                    nbands = -30,
                    spinpol = False,
                    usesymm = False)
poissonsolver = PoissonSolver()
correction = DipoleCorrection(poissonsolver, 2) # 2 == z-axis
calc = GPAW(poissonsolver=correction)
calc.attach(calc.write,1,gpwdat)
slab.set_calculator(calc)

I have attached also one of the output file and the corresponding structure.
I haven't tried yet to run first in the LCAO mode and than to continue this
way.

Thank you
Isabela Man
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