Dear Tom Thankyou for your kind reply.I checked my data witn phenix.xtriage and there are good anomalous signal (>0.05)in all the resolution shells. Also the systematic absences show it is P43212.Still i couldnt solve using phenix.Where is the thing going wrong? Xtriage results also showed no twinning. My previous message: I am using phenix1.4-4 version. In autosol, got the score of 10.24 for one iodine soaked data. FOM:0.27 and only 54 residues ( that too wrongly) were built out of 129.(CC=0.4), R=0.49 and Rfree=0.574. Regrading the data quality, Rsym:0.0448, Ranom:0.055, Resln:25.0-2.6A Spacegroup is P43212, completeness:99.4%, Multiplicity:11.7, anomalos signal is 1.52 at lowest resoln and higher in high resolution shells. What might be reason for not able to solve this structure?