# Brownian Dynamics Parameters **URL:** \ **Category:** User discussions\ **Created:** [January 11, 2021, 1:58pm UTC](https://gromacs.bioexcel.eu/t/brownian-dynamics-parameters/1419 "2021-01-11T13:58:09Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![dalip](https://avatars.discourse-cdn.com/v4/letter/d/b19c9b/32.png) [@dalip](https://gromacs.bioexcel.eu/u/dalip)\ **Post date:** [January 11, 2021, 1:58pm UTC](https://gromacs.bioexcel.eu/t/brownian-dynamics-parameters/1419/1 "2021-01-11T13:58:09Z")
GROMACS version: GROMACS modification: Yes/No Is anyone has experience doing Brownian dynamics using Gromacs for any kind of polymer? I need help in setting up some of the control parameters. I am aware of bd integrator and friction coefficient but it seems not working for my system. Any help will be appreciated! ---
**Author:** ![alevilla](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/alevilla/32/439_2.png) [@alevilla](https://gromacs.bioexcel.eu/u/alevilla)\ **Post date:** [January 15, 2021, 5:00pm UTC](https://gromacs.bioexcel.eu/t/brownian-dynamics-parameters/1419/2 "2021-01-15T17:00:43Z")
Hi, I can not understand exactly what is your problem. But maybe you can look at this post > [@BD stops after some steps](https://gromacs.bioexcel.eu/t/bd-stops-after-some-steps/918): > > GROMACS version: 2020.3 GROMACS modification: No I am performing Brownian Dynamics with hard spheres. But the simulation stops after a random number of steps, Gromacs keeps running but I don’t have evolution on the number of steps in any output file. First I was using only the C12 part of the LJ potential and I thought this problem could be due to two particles getting to close together and the potential getting to big. So I added the C6 term, the problem took longer to appear, the simulation… or other posts in the forum on brownian dynamics Best regards Alessandra