kuoli2010
Dears,
May I know how to ignore the first iteration? If the structure fell into a wrong minimum and I want to add some constrain to avoid it, usually it runs into the same minimum with the lowest Rwp without considering the constrain at the first iteration. I remember there is a command but I can not find it...
alancoelho
I'm not sure what is meant by ignore the first iteration. The program calculates Ycalc in the first iteration using parameters as defined in the INP file. If a different Ycalc is wanted in the first iteration then change the parameters.
johnsoevans
If I understood the question, the other thing you can do is remove "continue_after_convergence". TOPAS will then write the final Rwp model after the first convergence. Then rerun the file with continue_after_convergence back in.
As Alan said, we'd often just change e.g. a scale factor or zero point to start the refinement in a different place.