Hi, I'm using phenix for refinement and I keep getting an error. My DNA strand has a bromo-uridine in it and phenix.refine keeps crashing on this nucleotide. Here is the error: Number of atoms with unknown nonbonded energy type symbols: 40 "ATOM 2770 P BRU P 5 .*. P " "ATOM 2771 O1P BRU P 5 .*. O " "ATOM 2772 O2P BRU P 5 .*. O " "ATOM 2773 O5* BRU P 5 .*. O " "ATOM 2774 C5* BRU P 5 .*. C " "ATOM 2775 C4* BRU P 5 .*. C " "ATOM 2776 O4* BRU P 5 .*. O " "ATOM 2777 C1* BRU P 5 .*. C " "ATOM 2778 N1 BRU P 5 .*. N " "ATOM 2779 C6 BRU P 5 .*. C " ... (remaining 30 not shown) Here is what I have in my pdb: ATOM 2901 P BRU E 5 33.977 -16.324 24.303 1.00 27.21 P ATOM 2902 O1P BRU E 5 34.027 -15.724 22.919 1.00 28.22 O ATOM 2903 O2P BRU E 5 33.857 -15.340 25.393 1.00 25.06 O ATOM 2904 O5* BRU E 5 32.721 -17.236 24.418 1.00 28.02 O ATOM 2905 C5* BRU E 5 32.487 -18.228 23.495 1.00 28.50 C ATOM 2906 C4* BRU E 5 31.047 -18.347 23.082 1.00 32.59 C ATOM 2907 O4* BRU E 5 30.337 -18.858 24.152 1.00 28.61 O ATOM 2908 C1* BRU E 5 29.369 -17.891 24.535 1.00 29.63 C ATOM 2909 N1 BRU E 5 29.279 -17.855 25.962 1.00 29.72 N ATOM 2910 C6 BRU E 5 30.426 -17.755 26.799 1.00 30.57 C ATOM 2911 C5 BRU E 5 30.251 -17.738 28.232 1.00 30.89 C ATOM 2912 BR BRU E 5 31.869 -17.591 29.321 1.00 57.08 Br ATOM 2913 C4 BRU E 5 28.917 -17.845 28.826 1.00 30.70 C ATOM 2914 O4 BRU E 5 28.768 -17.825 30.033 1.00 29.36 O ATOM 2915 N3 BRU E 5 27.785 -17.945 27.981 1.00 29.36 N ATOM 2916 C2 BRU E 5 27.961 -17.966 26.552 1.00 29.05 C ATOM 2917 O2 BRU E 5 26.994 -18.064 25.848 1.00 35.29 O ATOM 2918 C3* BRU E 5 30.464 -17.006 22.751 1.00 34.58 C ATOM 2919 C2* BRU E 5 29.845 -16.605 23.968 1.00 33.10 C ATOM 2920 O3* BRU E 5 29.526 -17.213 21.768 1.00 37.93 O I have already run a BRU molecule through ReadySet and when I use the cif file generated from this phenix.refine will run through but when the Bromine atom is in the structure has a large negative density peak in the Fo-Fc map. I think it may just be a naming thing. BRU is already in the monomer library so I don't understand why I get an error at first also without the readyset cif file. Any suggestions? Thanks, Krystle