A complete sample that has been given number 123 should have two attached data files (at minimum): 123.cif and 123.crt. You are free to attach as many data files to each sample as you wish � some people include gif images, ort files for ORTEP renderings, pdb files, and so forth.� The crt file in particular has special significance: it contains coordinate data about the unit cell observed in this sample and is required for JaMM (a Java applet for molecular visualization) to function.� You may include multiple crt files depicting alternate views of the sample for users to switch between if you wish; in such a case the crt file named 123.crt would describe the default view.�