# Positive potential during energy minimization **URL:** \ **Category:** User discussions\ **Tags:** forcefield, mdp-parameters, mdrun\ **Created:** [July 22, 2024, 1:01am UTC](https://gromacs.bioexcel.eu/t/positive-potential-during-energy-minimization/9702 "2024-07-22T01:01:44Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![aahil1412](https://avatars.discourse-cdn.com/v4/letter/a/94ad74/32.png) [@aahil1412](https://gromacs.bioexcel.eu/u/aahil1412)\ **Post date:** [July 22, 2024, 1:01am UTC](https://gromacs.bioexcel.eu/t/positive-potential-during-energy-minimization/9702/1 "2024-07-22T01:01:45Z")
GROMACS version: 2021.5 GROMACS modification: Yes/No I am new to molecular dynamics and using GROMACS. I am simulating anime-based organic solvents using an OPLS-AA force field. I have generated all the parameters for the itp and gro files using LigParGen. Energy minimization gives a value in the range of -1e5 for most compounds. However, for a few compounds, it is in -5e3; for some, it is positive in the e4 or e5 range. I saw a similar thread with a person getting the same error: [Energy minimization\_ potential positive - User discussions - GROMACS forums (bioexcel.eu)](https://gromacs.bioexcel.eu/t/energy-minimization-potential-positive/7744). But I get an error in the later stages of the simulation. To check if I was getting molecular overlap, I reduced the number of molecules in these cases from a few hundred to 2. Even in this case, I was getting a positive potential energy. If I continue the simulation with this minimization, I get errors during the production stage of either the molecule drifting far away or bind angle becoming more than 30 degrees. I am not sure how to proceed. At this point, I have already run the simulation for 40 compounds, and I would not want to change the forcefield for the remaining 20 compounds since I want some homogeneity in the forcefield. Thank you