Hi Curt > Was > _diffrn_radiation_wavelength_determinaton > in a previous list? I can't remember. Yes: that was the one item added to the dictionary at the release of version 2.4.1: http://www.iucr.org/__data/iucr/cifdic_html/1/cif_core.dic/Idiffrn_radiation_wavelength_determination.html Regards Brian