Dear users,
I am trying to create a polymer containing N number of beads with each bead having a self propulsion force whose direction should change with respect to time in each time step. I tried using the fix addforce and lineforce but none seemed to work.
Should I try something else or will I have to create a new fix entirely?
The result should be somewhat like the article: https://doi.org/10.1103/PhysRevLett.121.217802
The primary problem is that each bead would have a different direction of force in any given instant of time.
Kindly suggest.
Thank you in advanced
Dear users,
I am trying to create a polymer containing N number of beads with each bead having a self propulsion force whose direction should change with respect to time in each time step. I tried using the fix addforce and lineforce but none seemed to work.
both fixes *do* work, but they cannot implement this kind of model.
Should I try something else or will I have to create a new fix entirely?
implementing this through a fix is an option. but it is not a trivial operation.
implementing this a custom angle style would be another (provided,
that you require special_bonds lj/coul 0.0 1.0 1.0 and that there are
no other angle interactions present)
The result should be somewhat like the article: https://doi.org/10.1103/PhysRevLett.121.217802
The primary problem is that each bead would have a different direction of force in any given instant of time.
i disagree with this assessment. the major problem is identifying the
neighboring atoms connected through bonds and computing their
orientation vector. this is impossible to do from the LAMMPS input,
might be possible (but very slow) through using python functions, but
is more straightforward to implement in C++ source code. since this is
always about the same triples of atoms, implementing this via an angle
style seems the most straightforward to me.
axel.
Thankyou for the prompt response.
I tried using angle style harmonic, it does work but not the way I want the system to work.
If the self-propulsion force is tangent to the backbone of the polymer for every bead the polymer must collapse into a globulelike structure,
Am I missing something ??
Ajesh Saviour
You are missing the whole point.
Thank you for your suggestion. I was really missing the whole point. The idea of using a custom angle style changes the system the way i wanted.
Ajesh Saviour
Department of Chemistry
National Institute of Technology, Rourkela