&GLOBAL
  PROJECT H2ion
  RUN_TYPE ENERGY
&END GLOBAL

&FORCE_EVAL
  METHOD Quickstep
  &DFT
    ! data-files for basis-set and pseudo-potentials
    BASIS_SET_FILE_NAME HFX_BASIS  
    POTENTIAL_FILE_NAME POTENTIAL
    
    &MGRID              ! resolution of finest grid, higher values give more accurate results
      CUTOFF 400
    &END MGRID

    &POISSON            ! Non periodic calculation needs Poisson solver
      PERIODIC NONE
      PSOLVER  WAVELET
    &END POISSON
    
    &SCF                 ! need to achieve SCF-convergence at large H-H distances
      &OT
        PRECONDITIONER FULL_ALL
      &END OT
    &END SCF
    
    CHARGE 1             ! H2 cation is positively charged...
    MULTIPLICITY 2       ! ...and therefore in a doublet spin state...
    LSD                  ! ...so that we have to run an unrestricted Kohn-Sham calculation
    
    &XC                  ! Exchange and Correlation settings
      &XC_FUNCTIONAL
        &PBE
          SCALE_X 0.5   ! amount of PBE eXchange (vary consistently with the HF/FRACTION)
          SCALE_C 1.0    ! amount of PBE Correlation. DO NOT VARY!!!!!!
        &END
      &END XC_FUNCTIONAL
      &HF
        FRACTION 0.5    ! amount of HF eXchange (vary consistently with PBE/SCALE_X)
        &SCREENING
          EPS_SCHWARZ 1.0E-10
        &END
      &END HF
    &END XC
  &END DFT

  &SUBSYS
    &TOPOLOGY
      &CENTER_COORDINATES  ! keep atoms away from box borders, would confuse Poisson solver
      &END
    &END
    &CELL
      ABC 15.0 15.0 15.0
      PERIODIC NONE  ! Non periodic calculation. 
    &END CELL
    &COORD
       H    0.0   0.0   0.0
       H    0.42  0.0   0.0  ! vary H-H distance to record dissociation profile
    &END COORD
    &KIND H
      BASIS_SET DZVP-GTH
      POTENTIAL GTH-PBE-q1
    &END KIND
  &END SUBSYS
&END FORCE_EVAL