There are many reasons why this could have ocurred.
One is that your NCS operator is very close to being a crystallographic
one.
But you need to give more details of the problem before I can comment
sensibly
Eleanor
Sun Tang wrote:
Dear All,
In refining my structure (two molecules in au) that was solved with molecular
replacement, refinement starting with restrained lowered the R-free to about
0.35 while with NCS increased the R-free to 0.55. Does it imply that two
molecules are quite different or something wrong with the refinement?
Thank you very much for your suggestions?
Best wishes,
Sun Tang
