lattice_vector 4.17970000 0.00000000 0.00000000 lattice_vector 0.00000000 2.66690000 0.00000000 lattice_vector 0.00000000 0.00000000 16.26955000 atom 1.27982456 0.00000000 6.26955000 O atom 2.08985000 1.33345000 5.45952414 Si atom 2.89987632 0.00000000 4.64949828 O atom 0.81002632 1.33345000 4.17970000 O atom 0.00000000 0.00000000 3.36967414 Si atom 3.36967460 1.33345000 2.55964828 O constrain_relaxation .true. atom 1.27982460 0.00000000 2.08985000 O constrain_relaxation .true. atom 2.08985000 1.33345000 1.27982414 Si constrain_relaxation .true. atom 2.89987636 0.00000000 0.46979828 O constrain_relaxation .true. atom 0.81002636 1.33345000 0.00000000 O constrain_relaxation .true.