[phenixbb] Questions about phenix.refine with twin_law

Keitaro Yamashita yamashita at castor.sci.hokudai.ac.jp
Fri Dec 24 21:21:43 PST 2010

Dear Phenix developers,

I'm working with pseudo-merohedrally twinned data (fraction 45%),
using Phenix-dev-616.

I have three questions about phenix.refine with twin_law.
(running on the command line)

During refinement with twin_law, the log file says x-ray target
function is set to "twin_lsq_f".
Does it mean, we cannot use maximum likelihood target for twinned data?
If so, is it recommended to refine without twin_law at first several cycles?

When I tried to refine using the model refined without twin_law,
the target function was still ml, not twin_lsq_f although I specified twin_law.
Is this a bug?

When I used twin_law option, in the table "R-free likelihood based estimates",
"Scale factor" were None in all resolution bins.
Cannot scale factor be calculated during twin refinement?

Thanks in advance and Wishing you the best holidays,


More information about the phenixbb mailing list