There is in my opinion no "right" method. The question is what are you trying to do?
Case 1: A structure with fixed positions or a problem where you "don't care" about minor forces, e.g. calculating a simple bulk structure. Then just "runsp -cc 0.0001 -ec 0.0001" is fine. (I prefer to use -cc as well as the default -ec). Case 2: A simple structure where there might be minor forces that you do care about. Then something like "runsp -cc 0.0001 -ec 0.0001 -fc 1" first and check the forces. Iff they are too large for you, then "save -f -d PreMin ; runsp -cc 0.001 -ec 0.0001 -min" or similar. Case 3: A more complex structure where you know the positions are not quite right. I suggest using something like runsp -cc 0.01 -ec 0.1 -fc 4 save -f -d PreMin runsp -cc 0.001 -ec 0.0001 -fc 1 -min This avoids converging too much at first when you know the result won't be right until the internal minimization has been done. In addition, MSR1a often works better when started from a partial minimization where the density and pseudo-charges are somewhat converged. For a large problem add "-noHinv", I have had problems with -min and -it in the past. On Mon, Oct 15, 2018 at 9:03 AM karima Physique <physique.kar...@gmail.com> wrote: > Dear Wien2k user; > > According to user guide, after a SCF cycle with runsp -fc 1 we continue > with run runsp -min > I want to know which of these two methods is the correct one: > 1) > runsp -fc 1 > runsp -min > runsp -min -fc 0.5 -ec 0.0001 -cc 0.001 > > or > 2) > runsp -fc 1 > runsp -min -fc 0.5 -ec 0.0001 -cc 0.001 > -- Professor Laurence Marks "Research is to see what everybody else has seen, and to think what nobody else has thought", Albert Szent-Gyorgi www.numis.northwestern.edu ; Corrosion in 4D: MURI4D.numis.northwestern.edu Partner of the CFW 100% program for gender equity, www.cfw.org/100-percent Co-Editor, Acta Cryst A
_______________________________________________ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien SEARCH the MAILING-LIST at: http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html