minimal_example.py

#!/bin/env python

import gc

from ase.build import bulk, cut
from gpaw import GPAW, mpi

my_comm = mpi.world.new_communicator([mpi.world.rank])
my_output = "log_%d" % mpi.world.rank

def chunker(seq, size):
    return (seq[pos:pos + size] for pos in range(0, len(seq), size))

calculations = []
for i in range(100):
    b = bulk("GaP", crystalstructure="zincblende", cubic=True, a=5.4504)
    cell = cut(b, a=(2,0,0), b=(0,2,0), c=(0,0,1))
    cell.set_pbc((True, True, False))
    pos = cell.positions.copy()
    cell.rattle(seed=i)
    cell.positions[:,2] = pos[:,2]
    calculations.append(cell)

for ichunk, group in enumerate(chunker(calculations, mpi.world.size)):
    if mpi.world.rank < len(group):
        calc = GPAW(mode='pw', xc='LDA', h=0.3, communicator=my_comm, txt=my_output)
        atoms = group[mpi.world.rank].copy()
        atoms.set_calculator(calc)
        print("Success!", ichunk, mpi.world.rank, atoms.get_potential_energy())
        del atoms
        del calc
        gc.collect()
    mpi.world.barrier()