hi all During refinement of a structure i used intensity based twin refinement in refmac. It decreased the R and Free factors by about 10% but the Rms bond length and Rms bond angles increased substantially. Could anyone tell me what could possibly be done to bring the rms values to normal and acceptable range. Resolution of data is 1.6A and we were stuck at R and Free R of 27 and 31 respectively before Twin refinement inspite of having excellent e- density. Twin fraction as estimated by refmac was 0.528. thanks in advance -- Sudhir Kumar Research Scholar Structural Biology Laboratory SLS, JNU, New Delhi-110067
