TITL quartz
CELL 4.913   4.913   5.404  90.00  90.00 120.00            ! cell parameters
SG P 32 2 1                                                ! space group 
ATOM Si Si 0.47 0. 2/3                                     ! Atomic position in asymetric unit
ATOM O  O  0.4146 0.78543 0.0109                           ! Atomic position in asymetric unit
GEN_EQUIV_ATOMS                                            ! apply all symmetry operators of the space group to calculate atomic positions in the unit cell 
SUPERCELL 2 2 2                                            ! supercell indices: calculate all atomic positions (new space group = P1)
WAVE X_Cu                                                  ! X-Ray beam (Kalpha radiation)
GEN_HKL 2theta_min=0 2theta_max= 120 PAT                   ! hkl list generation, structure factors calculation + pattern simulation