fix npt vs relax/box

Hello everyone!
I am trying to figure out the best way to optimize lengths of triclinic cell with oredered system of amphiphiplic molecules. Looks like this can be done via “fix box/relax” and “fix np*”. Mechanics of these methods are different but if we talk about results, will they be same? Which way is cheaper?

Thanks!

Hello everyone!
I am trying to figure out the best way to optimize lengths of triclinic cell
with oredered system of amphiphiplic molecules. Looks like this can be done
via "fix box/relax" and "fix np*". Mechanics of these methods are different
but if we talk about results, will they be same? Which way is cheaper?

you cannot compare them. they serve different purposes.
fix box/relax is meant to be used in combination with the minimize
command, i.e. for systems at 0K, while fix npt/nph is an integrator
for systems at finite temperature.

axel.