McStas Single_crystal needs explicit barns=1 parameter for files with |F2| in barns #2112
Description
During a Single_crystal related debugging session with @Lomholy and @mads-bertelsen we found that the McStas Single_crystal no longer automatically uses units of barns when a file contains e.g. # column_F2 6 norm of scattering factor |F|^2 in [barn].
When using a CIF file this is however set automatically since the related cif2hkl function (and underlying cif2hkl command) returns barns
A correction should be done, based on presence of keyword barns in related line in the input file header.
As a workaround you may use the barns=1 flag.