Lorentz, polarization and absorption corrections are assumed to have been applied to the data in the .HKL file. If SHELXA is used for the absorption corrections, it will have read a file name.raw (containing direction cosines) and written 'name.HKL' (without cosines). Since SHELXA can read a SHELXL_93 .INS file, empirical absorption corrections (which require SHELXA to calculate Fc) may be applied more than once to the original data in the course of a structure determination simply by running SHELXA immediately before SHELXL_93 with the same .INS file. Note that there are special extensions to the .HKL format for Laue and powder data, as well as for twinned crystals which cannot be handled by a TWIN instruction alone.
In general the .HKL file should contain all measured reflections without rejection of systematic absences or merging of equivalents. The systematic absences and R(int) for equivalents provide an excellent check on the space group assignment and consistency of the input data. Since complex scattering factors are used throughout by SHELXL_93 it is important NOT to average Friedel opposites in preparing this file.