Berk Hess authored Sep 18, 2023 and Magnus Lundborg committed Sep 18, 2023

The deform option would scale the coordinates and did not correct
the velocity of atoms when they were shifted by a periodic vector.
These issues have been fixed now, which makes the deform option
suitable for shear flows.
To initialize the flow the mdp option deform-init-flow has been added.

Fixes #4607

Closes #4607