Dear all,
I am trying to simulate a system composed of rod-like active particles ( I am using 10Aug15 version). To do this, I have set particles in a row for every rod-like particles and made them rigid as rigid bodies. I have set heads and tails atoms as two separated groups. Then, I need to obtain unit vectors in direction of rod’s axis. The problem is being atom_style of fix addforce command as well as variable … atom … . To obtain unit vectors in direction of rod’s axis I have tried on two ways: