[lammps-users] fix deform to perform trigonal deformation

Hello All,

Can anyone give me a hint about the appropriate fix deform command to perform a trigonal deformation.

The trigonal deformation involve a tensile strain along [111] direction and simultaneous compression in the [2(bar)11] and [011(bar)].


You can use fix deform to expand one dim and compress others. See the
doc page. If the formula for the box lengths as a function of time
is something complex for trigonal deformation (i.e. something not supported
by the current fix deform options), it wouldn't be hard to add a deformation
that operates using a time-dependent variable.

Also, look at the "volume" option for fix deform, which compresses other
dims to preserve the volume when one dim expands.