This is a perfect case for potential static/statistical disorder. See 

The 1.8 å crystal structure of a statically disordered 17 base-pair RNA duplex: 
principles of RNA crystal packing and its effect on nucleic acid structure
1 Sapan A Shah1, 2, Axel T Brunger1, 2,

To investigate/solve this, you should run Phaser-SAD using partial model 
phases, look for any anomalous atoms like Cl- or S, then auto rebuild to get 
the right registration. This will only work, however, if the crystal is not 
statically/statistically disordered. If it is, then you will see less-strong 
peaks at several registers, and you will have a tricky case on your hands.


-----Original Message-----
From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Abhishek 
Sent: Monday, September 19, 2016 11:48 AM
Subject: [ccp4bb] multiple similar solutions in phaser

Dear all, 

I am trying to solve the structure of a collagen triple helix using phaser. The 
crystal diffracts to 2.0 A in P1 space group. Matthew's coefficient suggests 4 
molecules in the asu. When I tried to search for 5 components, phaser gave 8 
solutions each containing 4 triple helices.  The LLG scores are in the range of 
2200 and TFZ around 15. 
All 8 solutions are similar except that the triple helices slide either up or 
down with respect to each other in different solutions. 

Refinement of the top solution using default settings in phenix resulted in the 
following statistics. 

                             start         final
  R-work:           0.5000        0.4003
  R-free:            0.4989        0.4586
  RMS(angles):      1.82            1.74
  RMS(bonds):     0.013          0.009

I am relatively new to crystallography and would appreciate any help in 
understanding why I am getting multiple solutions and if there is a way to 
reconcile the results into a single solution. 

Thank you

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