Dear group I have a crystal data diffracted around 2.9 A*, during the data reduction HKL2000 not convincingly showed the space group (indexed in lower symmetry p1), while the mosflm given C-centered Orthorhombic, and again with little play around HKL2000 given CO, now the model for molecular replacement with closest identity of 31 given a contrast of 2, score 0.30 and wrfac 0.60. but "balbes" uses different models with lesser identity,
no matter which way I am going the rFree keep on increasing during refinement in refmac, when I build the model in coot with deletion and addition of residue it starts with relatively low but gradually rises through almost all cycles although model fits to the density well and residue are building, coot validation parameters are also reasonable OK for geometry, rotamer, density fit,.. now my question.... * where should i first check for possible correction? * In molecular replacement what should be the red line for identity and related criteria? * if initial rFree starts around 50, how likely that its not the right way? * my rms bond angle is close to 1 while the bond length is 0.01 and chiral 0.1 concludes what is serious? *sincere apology for amateur query* if any... thanks in advance pramod -- ************************************************ Pramod Kumar. Graduate Student. Crystallography lab. Department Of Biotechnology. Indian Institute Of Technology Roorkee Uttranchal.247667 India +919359189657. ************************************************