lattice_vector 4.21100000 0.00000000 0.00000000 lattice_vector 0.00000000 4.21100000 0.00000000 lattice_vector 0.00000000 0.00000000 4.21100000 atom 0.000000 0.000000 0.000000 Mg atom 0.500000 0.500000 0.500000 O