Dear all,
I did a minimization for a polycrystal structure and found that it takes much less timesteps for a bigger structure to minimize that a smaller one. Also in the smaller structure the grain boundaries are diffusing into each other a lot where as such an effect is much less in the bigger structure.
Is such a thing alright and can i reduce my etol and ftol .I am currently using.
minimize 1.e-10 1.e-10 10000 10000
I will use this polycrystal structure to run some tensile tests.
Thanks.
regards,
Ashish
Dear all,
I did a minimization for a polycrystal structure and found that it takes
much less timesteps for a bigger structure to minimize that a smaller one.
Also in the smaller structure the grain boundaries are diffusing into each
other a lot where as such an effect is much less in the bigger structure.
Is such a thing alright and can i reduce my etol and ftol .I am currently
using.
things are never this easy and there is never just one single parameter
that determines the outcome.
what you describe seems much more the outcome of a less than perfect
procedure to create your initial geometry. the relative error of that will
be less with growing system size. it could also be just by chance. it is a
bad sign, if your structure changes significantly during minimization.
please also keep in mind, that minimization will not find *the* minimum,
but just *a* minimum. there are a very large number of local minimal in any
structure like yours and your initial configuration will have a large
impact on which of those will be found.
axel