I am on the learning phase of using XPLOR, and I would like to know what TYPE and CHARge are assigned to each N atoms in an azide, e.g. in CH3N3 when writing it's topology file. Right now, I am using the information found in Engh and Huber (Acta Cryst, A47, 392-400), but I do not see any values associated with azide. I would appreciate any help. Thanks.