# Subject: LINCS Warnings During Energy Minimization of PSM Bilayer

**URL:** <https://gromacs.bioexcel.eu/t/subject-lincs-warnings-during-energy-minimization-of-psm-bilayer/11906>\
**Category:** User discussions\
**Created:** [April 10, 2025, 9:01am UTC](https://gromacs.bioexcel.eu/t/subject-lincs-warnings-during-energy-minimization-of-psm-bilayer/11906 "2025-04-10T09:01:17Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![ip919](https://avatars.discourse-cdn.com/v4/letter/i/ba8739/32.png) [@ip919](https://gromacs.bioexcel.eu/u/ip919)\
**Post date:** [April 10, 2025, 9:01am UTC](https://gromacs.bioexcel.eu/t/subject-lincs-warnings-during-energy-minimization-of-psm-bilayer/11906/1 "2025-04-10T09:01:18Z")

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Dear all,

I’m using the standard workflow for preparing a PSM lipid bilayer as suggested in the Martini 3 tutorials. I successfully generated the membrane.gro file using insane.py and proceeded to energy minimization using the following commands:

**gmx grompp -f martini\_v2.x\_new-rf-em.mdp -c membrane.gro -p topol.top -o psm.tpr  
gmx mdrun -s psm.tpr -v -c minimized.gro**

I’m using the martini\_v2.x\_new-rf-em.mdp file provided in the [M3-Lipid-Parameters/openbeta at main · Martini-Force-Field-Initiative/M3-Lipid-Parameters · GitHub](https://github.com/Martini-Force-Field-Initiative/M3-Lipid-Parameters/tree/main/openbeta)

However, during the minimization step, I encountered a large number of LINCS warnings, and the minimization was not completed successfully.  
\*\*Program: gmx mdrun, version 2021.4-Ubuntu-2021.4-2  
Source file: src/gromacs/mdlib/constr.cpp (line 241)

Fatal error:  
Too many LINCS warnings (1463)  
If you know what you are doing you can adjust the lincs warning threshold in  
your mdp file  
or set the environment variable GMX\_MAXCONSTRWARN to -1,  
but normally it is better to fix the problem.\*\*

Has anyone experienced similar issues, or is there something I might be overlooking in the setup?

Any help or suggestions would be greatly appreciated.

Best regards,  
Ishwar

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**Author:** ![etum2](https://avatars.discourse-cdn.com/v4/letter/e/8dc957/32.png) [@etum2](https://gromacs.bioexcel.eu/u/etum2)\
**Post date:** [April 23, 2025, 9:27am UTC](https://gromacs.bioexcel.eu/t/subject-lincs-warnings-during-energy-minimization-of-psm-bilayer/11906/2 "2025-04-23T09:27:11Z")

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I have the same problem! Did you solve it yet, if yes what did you do?