HTBZ-HMA. The 2-(4'-thiazolyl) benzimidazole-N, N' molecule was positionally disordered over two sites in this structure. To help maintain reasonable ADP and bond length values for the disordered sites, SAME, SIMU, and RIGU restraints were applied. Hydrogen atoms bound to carbon atoms were located in the different Fourier map and were geometrically constrained using the appropriate AFIX commands.