@SET NREP 1
&FORCE_EVAL
  STRESS_TENSOR ANALYTICAL
  &DFT
    &KPOINTS
      SCHEME MONKHORST-PACK 2 2 2
    &END KPOINTS
    &POISSON
      PERIODIC XYZ
      POISSON_SOLVER PERIODIC
      &EWALD
        ALPHA [bohr^-1] 1.0
        EWALD_TYPE SPME
      &END EWALD
    &END POISSON
    &PRINT
      &KS_CSR_WRITE
        BINARY .TRUE.
        COMMON_ITERATION_LEVELS 1
        THRESHOLD 1.0E-4
        UPPER_TRIANGULAR .TRUE.
      &END KS_CSR_WRITE
      &S_CSR_WRITE
        BINARY .TRUE.
        COMMON_ITERATION_LEVELS 1
        THRESHOLD 1.0E-4
        UPPER_TRIANGULAR .TRUE.
      &END S_CSR_WRITE
    &END PRINT
    &QS
      METHOD xTB
      &XTB
      &END XTB
    &END QS
    &SCF
      ADDED_MOS 100
      EPS_SCF 1.e-6
      IGNORE_CONVERGENCE_FAILURE
      MAX_SCF 500
      SCF_GUESS MOPAC
      &MIXING
        ALPHA 0.15
        METHOD DIRECT_P_MIXING
      &END MIXING
      &PRINT
        &RESTART off
        &END RESTART
        &RESTART_HISTORY off
        &END RESTART_HISTORY
      &END PRINT
      &SMEAR
        ELECTRONIC_TEMPERATURE 500
        METHOD FERMI_DIRAC
      &END SMEAR
    &END SCF
  &END DFT
  &SUBSYS
    &CELL
      ABC 5.431 5.431 5.431
      MULTIPLE_UNIT_CELL ${NREP} ${NREP} ${NREP}
    &END CELL
    &COORD
      SCALED
      Si     0.000000    0.000000    0.000000
      Si     0.490000    0.500000    0.000000
      Si     0.500000    0.000000    0.500000
      Si     0.000000    0.500000    0.500000
      Si     0.255000    0.250000    0.250000
      Si     0.250000    0.755000    0.750000
      Si     0.750000    0.250000    0.755000
      Si     0.750000    0.750000    0.255000
    &END COORD
    &TOPOLOGY
      MULTIPLE_UNIT_CELL ${NREP} ${NREP} ${NREP}
    &END TOPOLOGY
  &END SUBSYS
&END FORCE_EVAL

&GLOBAL
  PRINT_LEVEL LOW
  PROJECT Si
  RUN_TYPE GEO_OPT
&END GLOBAL

&MOTION
  &GEO_OPT
    MAX_DR 0.0001
    MAX_FORCE 0.00001
    MAX_ITER 2
    OPTIMIZER LBFGS
    RMS_DR 0.00003
    RMS_FORCE 0.000003
  &END GEO_OPT
&END MOTION
