 PREC = Normal    ! standard precision 
 ENMAX = 400      ! cutoff should be set manually
 ISMEAR = 0 ; SIGMA = 0.1
 IBRION = 1       ! use DIIS algorithm to converge
 NFREE = 2        ! 2 independent degrees of freedom
 NSW = 10         ! 10 ionic steps
 EDIFFG = -0.02   ! forces smaller 0.02 A/eV
