I’d like to know when coupling should be considered or may not be considered in controling pressure (fix npt).
Specifically, what cases would correspond to them respectively?
For solid (crytsalline) should we consider coupling usually?
In what cases can we neglect coupling?
If I omit couple keyword, what is default value of it, “appropriate coupling” or “none”?
Best regards,
Luke
2011/7/25 JhonY. I. <[email protected]...>:
I'd like to know when coupling should be considered or may not be considered
in controling pressure (fix npt).
Specifically, what cases would correspond to them respectively?
you wan to use the coupling whenever it is physically meaningful
to enforce the ratio of cell dimensions.
For solid (crytsalline) should we consider coupling usually?
In what cases can we neglect coupling?
it really depends on the individual case. however, for solids coupling
may have less impact than for liquids. in the latter case, when using
long-range electrostatics, there is a slight tendency to "flatten" you box.
If I omit couple keyword, what is default value of it, "appropriate
coupling" or "none"?
defaults are listed at the end of the documentation for the fix keyword
(in this case couple=none).
axel.