I have several small organic molecules constructed in ChemDraw and converted in Chem3D to .mol2 files. I can open them in Chimera but cannot seem to add charges to. I was simply using the add charge menu commands and AM1-BCC and assuming the structures would be read as nonstandard but antechamber reports an error with residue ****. The error log has no real indication of what the trouble might be. Are there additional steps I must take before assigning charges? The structures already have hydrogens added. An example .mol2 file is below: @<TRIPOS>MOLECULE **** 44 45 1 0 0 SMALL USER_CHARGES @<TRIPOS>ATOM 1 C -2.8306 2.5311 -0.9622 C.2 1 **** 0.0000 2 C -2.8728 1.1718 -1.0363 C.2 1 **** 0.0000 3 C -4.0552 0.3840 -0.9622 C.1 1 **** 0.0000 4 C -1.6082 0.4134 -1.1450 C.2 1 **** 0.0000 5 N -5.0052 -0.2769 -0.8917 N.1 1 **** 0.0000 6 O -1.8883 -0.9222 -1.2800 O.3 1 **** 0.0000 7 O -0.4722 0.8459 -1.1451 O.2 1 **** 0.0000 8 C -0.8034 -1.8901 -1.1282 C.3 1 **** 0.0000 9 C -0.3965 -1.8485 0.3585 C.2 1 **** 0.0000 10 C -1.4383 -3.2075 -1.5077 C.3 1 **** 0.0000 11 N 0.6925 -2.6041 0.6991 N.am 1 **** 0.0000 12 O -1.0062 -1.1536 1.1745 O.2 1 **** 0.0000 13 C 1.2426 -2.6055 2.0833 C.3 1 **** 0.0000 14 C 2.4273 -3.5343 2.1380 C.ar 1 **** 0.0000 15 C -3.9592 3.4353 -0.8741 C.ar 1 **** 0.0000 16 C -3.7802 4.6664 -0.1923 C.ar 1 **** 0.0000 17 C -4.8234 5.5702 -0.0757 C.ar 1 **** 0.0000 18 C -6.0611 5.2454 -0.6673 C.ar 1 **** 0.0000 19 C -6.2633 4.0447 -1.3692 C.ar 1 **** 0.0000 20 C -5.2063 3.1490 -1.4690 C.ar 1 **** 0.0000 21 O -7.0408 6.1768 -0.5154 O.3 1 **** 0.0000 22 C 3.5525 -3.2801 1.3388 C.ar 1 **** 0.0000 23 C 4.6333 -4.1642 1.3545 C.ar 1 **** 0.0000 24 C 4.6017 -5.2952 2.1768 C.ar 1 **** 0.0000 25 C 3.4888 -5.5395 2.9865 C.ar 1 **** 0.0000 26 C 2.3994 -4.6635 2.9668 C.ar 1 **** 0.0000 27 H -1.8332 3.0176 -0.9495 H 1 **** 0.0000 28 H 0.0351 -1.5845 -1.7993 H 1 **** 0.0000 29 H -0.6942 -4.0150 -1.5686 H 1 **** 0.0000 30 H -1.9272 -3.1457 -2.4932 H 1 **** 0.0000 31 H -2.2150 -3.5214 -0.7935 H 1 **** 0.0000 32 H 1.1669 -3.2048 0.0167 H 1 **** 0.0000 33 H 1.5395 -1.5662 2.3712 H 1 **** 0.0000 34 H 0.4439 -2.9024 2.8058 H 1 **** 0.0000 35 H -2.8085 4.9012 0.2576 H 1 **** 0.0000 36 H -4.7042 6.5169 0.4530 H 1 **** 0.0000 37 H -7.2285 3.8279 -1.8322 H 1 **** 0.0000 38 H -5.3406 2.2282 -2.0442 H 1 **** 0.0000 39 H -7.9024 5.8992 -0.9622 H 1 **** 0.0000 40 H 3.5844 -2.3950 0.7014 H 1 **** 0.0000 41 H 5.5045 -3.9710 0.7250 H 1 **** 0.0000 42 H 5.4465 -5.9867 2.1870 H 1 **** 0.0000 43 H 3.4659 -6.4183 3.6333 H 1 **** 0.0000 44 H 1.5299 -4.8643 3.5946 H 1 **** 0.0000 @<TRIPOS>BOND 1 1 2 2 2 1 15 1 3 1 27 1 4 2 3 1 5 2 4 1 6 3 5 3 7 4 6 1 8 4 7 2 9 6 8 1 10 8 9 1 11 8 10 1 12 8 28 1 13 9 11 1 14 9 12 2 15 10 29 1 16 10 30 1 17 10 31 1 18 11 13 1 19 11 32 1 20 13 14 1 21 13 33 1 22 13 34 1 23 14 22 2 24 14 26 1 25 15 16 2 26 15 20 1 27 16 17 1 28 16 35 1 29 17 18 2 30 17 36 1 31 18 19 1 32 18 21 1 33 19 20 2 34 19 37 1 35 20 38 1 36 21 39 1 37 22 23 1 38 22 40 1 39 23 24 2 40 23 41 1 41 24 25 1 42 24 42 1 43 25 26 2 44 25 43 1 45 26 44 1 Thanks for any help you can provide. Dr. Jon N. Rumbley Assistant Professor Dept. of Pharmacy Practice and Pharmaceutical Sciences University of Minnesota-Duluth 127 LSci 1110 Kirby Dr. Duluth, MN 55812 Phone: 218-726-6047 email: jrumbley@d.umn.edu