BASF Instruction
BASF scale factors
Relative batch scale factors are included in the least-squares refinement
based on the batch numbers in the '.hkl' file. For batch number BN, the Fc^2
value is multiplied by the (BN-1)'th scale factor from the BASF instruction,
as well as by the overall scale factor. For batch number one (or zero), Fc is
multiplied by the overall scale factor, but not by a batch scale factor. The
least-squares matrix will be singular if there are no reflections with BN=1
(or zero), so the program considers this to be an error. Note that BASF scale
factors, unlike the overall scale factor (see FVAR) are relative to F^2, not
F. For twinned crystals, i.e. when either TWIN or HKLF 5 are employed, BASF
specifies the fractional contributions of the various twin components.