from ase import Atoms
from gpaw import GPAW, Mixer, ConvergenceError, PoissonSolver 
from gpaw.utilities.timing import Timer
from gpaw.eigensolvers.rmm_diis import RMM_DIIS
ps = PoissonSolver(nn='M', relax='GS', eps=1e-9)
es = RMM_DIIS(keep_htpsit=False)
from gpaw.hs_operators import MatrixOperator
MatrixOperator.nblocks = 3

class MyGPAW(GPAW):
        timer_class = Timer

a = 4.08
bulk = Atoms('Au4', positions=((0, 0 ,0),
                               (0.5, 0.5, 0),
                               (0.5, 0, 0.5),
                               (0, 0.5, 0.5)), pbc=True)

bulk.set_cell((a,a,a), scale_atoms=True)
bulk = bulk.repeat((6, 6, 6))
calc = MyGPAW(gpts=(192, 192, 192),
            maxiter=36,
            mode = 'fd',
            poissonsolver=ps,
            nbands = 4800,
            xc = 'LDA',
            width = 0.01,
            mixer = Mixer(0.10,3),
            eigensolver = es,
            txt = 'Au_bulk.out')

bulk.set_calculator(calc)
try:
    bulk.get_potential_energy()
except ConvergenceError:
    pass