&GLOBAL
  PRINT_LEVEL MEDIUM
  PROJECT_NAME quartz
  RUN_TYPE CELL_OPT
&END GLOBAL

&MOTION
  &CELL_OPT
    EPS_SYMMETRY 1e-4
    KEEP_ANGLES T
    KEEP_SPACE_GROUP T
    KEEP_SYMMETRY T
    MAX_ITER 1
    OPTIMIZER BFGS
  &END CELL_OPT
&END MOTION

&FORCE_EVAL
  METHOD QS
  STRESS_TENSOR ANALYTICAL
  &DFT
    CHARGE 0
    MULTIPLICITY 1
    &POISSON
      PERIODIC XYZ
      POISSON_SOLVER PERIODIC
      &EWALD
        ALPHA 1.0
      &END EWALD
    &END POISSON
    &QS
      METHOD XTB
      &XTB
        CHECK_ATOMIC_CHARGES F
        DO_EWALD T
      &END XTB
    &END QS
    &SCF
      EPS_SCF 1.E-5
      MAX_SCF 10
      SCF_GUESS ATOMIC
      &OT T
        MINIMIZER CG
        PRECONDITIONER FULL_ALL
      &END OT
      &OUTER_SCF T
        EPS_SCF 1.E-5
        MAX_SCF 10
      &END OUTER_SCF
    &END SCF
  &END DFT
  &SUBSYS
    &CELL
      ABC 4.9159998894 4.9159998894 5.4053997993
      ALPHA_BETA_GAMMA 90.00 90.00 120.00
      MULTIPLE_UNIT_CELL 1 1 1
      PERIODIC XYZ
      SYMMETRY MONOCLINIC_GAMMA_AB
    &END CELL
    &COORD
      Si   0.469699985         0.000000000         0.000000000
      Si   0.000000018         0.469700021         0.666666696
      Si   0.530300031         0.530300048         0.333333348
      O    0.413500032         0.266900007         0.119099996
      O    0.266900018         0.413500038         0.547566700
      O    0.733100016         0.146600017         0.785766692
      O    0.586499976         0.853400010         0.214233330
      O    0.853400027         0.586500031         0.452433344
      O    0.146600008         0.733100006         0.880900004
      UNIT angstrom
      SCALED  T
    &END COORD
    &TOPOLOGY
      MULTIPLE_UNIT_CELL 1 1 1
      NUMBER_OF_ATOMS 9
    &END TOPOLOGY
  &END SUBSYS
&END FORCE_EVAL
