Dear lammps users,
I am trying to simulate a system of big particles embedded in a fluid of srd particles.
I would like to add an external force on srd particles. I have followed the thread https://lammps.sandia.gov/threads/msg63030.html and compiled the modified version of fix_srd (attached therein), in order to implement the external force on srd particles.
My problem is that I have a constant number of srd particles inside big particles. I generate the initial configuration by randomly positioning the colloids and the srd particles. As you can see from the attached in.srd file, I perform the fix nve/limit command to partially remove the overlap. When I start the simulation run I have around 1000 srd particles inside big particles, and this number does not go to zero with increasing simulation time, on the contrary it oscillates about 1000. However, If I use the stable version of lammps 16Mar2018, the number of srd particles inside big particles decreases with simulation time, eventually becoming zero. I wonder why this does not occur with the modified version of fix_srd. I exclude the possibility that the external force might cause this problem because I verified that by setting the external force on srd particles equal to zero I still obtain 1000 srd particle inside big particles.
Thank you in advance.
in.srd (2.57 KB)