Dear users I have complex structure with ligand having sulfur atom in it. I am trying to minimize it but it fails giving the following error: (LIG) /home/usr/.local/UCSF-Chimera64-1.12/bin/amber16/bin/antechamber: Fatal Error! (LIG) Cannot properly run "/home/usr/.local/UCSF-Chimera64-1.12/bin/amber16/bin/sqm -O -i sqm.in -o sqm.out". I assume it's because of sulfur atom in ligand because I tried running it with out sulfur and it worked fine. I checked MMKT Atom database for sulfur file and it's already there: name = 'sulphur' symbol = 'S' mass = [(31.97207070, 95.02), (32.97145843, 0.75), (33.96786665, 4.21), (35.9670806, 0.02)] color = 'yellow' vdW_radius = 0.18 b_coherent = 2.847*fm b_incoherent = 0.188*fm b_coherent_deut = 2.847*fm b_incoherent_deut = 0.188*fm Any help would be highly appreciated. Thanks Sara