Thank you Wayne. I'll do what you suggested. But now I can not finish the run because of linking issue: .... MESSAGE [Protocol]: Iteration 8 done. MESSAGE [Protocol]: Performing analysis on calculated structures... MESSAGE [Protocol]: Analysis done. MESSAGE [Protocol]: NOE-restaint list (text) written (/home/vitaliy/sk45m/CCPN/ structure/sk4/rdcref/run2/structures/it8/noe_restraints). MESSAGE [Protocol]: Report for Merging-step written (/home/vitaliy/sk45m/CCPN/ structure/sk4/rdcref/run2/structures/it8/noe_restraints.merg ed). ############################################## # FormatConverter: executing readCoordinates # ############################################## Pick corresponding Ccp chain for ' ': 0: 'A' (122 res, molecule sk4) 1: Do not link Choose number: 0 Sequence code 999 for chain ' ' corresponds to which sequence Id for 'A' (122 res, molecule sk4)? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 Choose number: 999 Choose number: 999 Choose number: 999 Choose number: As you can see I have RDCs and FC tries to link residue 999 to protein sequence... Vitaliy