(no subject)

Hi all

I am planning to test the strength of one polymer chain, I only want to simulate one section of this polymer chain. I want to achieve it by applying the moving periodic boundaries along the pulling direction, as shown in figure below:
The dashed lines represent the boundary of the simulation box, the arrow represent the force exerted on the atoms and the moving direction of the left and right boundary. The shadowed region means virtual, namely in this figure, the first atom only has the right side in the simulation box, the last atom only has the left side in the simulation box.

Another problem is that, you can see there are two atoms on the moving periodic boundaries, I am not sure whether this is doable.

Can any one tell me which command can achieve it? I would really appreciate your kindly and timely help.

Best regards

As someone already posted, fix deform will increase
the size of the simulation box, and works with periodic BC.