!
!  Lattice vectors of simulation cell.
!  in order  a(x)  a(y)  a(z)
!            b(x)  b(y)  b(z)
!            c(x)  c(y)  c(z)
!
!  N.B. These are the vectors of the *primitive* rhombohedral
!  cell of Si2 in the diamond structure.
%block lattice_cart
2.6954645 2.6954645 0.0 
2.6954645 0.0       2.6954645
0.0       2.6954645 2.6954645
%endblock lattice_cart
!
! Atomic co-ordinates for each species.
! These are in fractional co-ordinates wrt to the cell.
!
%block positions_frac
Si 0.00 0.00 0.00
Si 0.25 0.25 0.25
%endblock positions_frac
!
! Analyse structure to determine symmetry
!
symmetry_generate
!
! Choose which pseudopotentials to use
! Either specify external files, or omit to generate a pseudopotential
!
%block species_pot
Si Si_00.usp
%endblock species_pot
!
! Specify M-P grid dimensions for electron wavevectors (K-points)
!
kpoint_mp_grid 4 4 4