# Mdrun 2024Seqmentation fault%

**URL:** <https://gromacs.bioexcel.eu/t/mdrun-2024seqmentation-fault/8096>\
**Category:** User discussions\
**Tags:** mdrun\
**Created:** [January 20, 2024, 7:03pm UTC](https://gromacs.bioexcel.eu/t/mdrun-2024seqmentation-fault/8096 "2024-01-20T19:03:51Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![lynn1](https://avatars.discourse-cdn.com/v4/letter/l/ee59a6/32.png) [@lynn1](https://gromacs.bioexcel.eu/u/lynn1)\
**Post date:** [January 20, 2024, 7:03pm UTC](https://gromacs.bioexcel.eu/t/mdrun-2024seqmentation-fault/8096/1 "2024-01-20T19:03:52Z")

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GROMACS version: 2021.4-Ubuntu-2021.4-2  
GROMACS modification: Yes/No  
Here post your question  
command : gmx mdrun -s nonequil.tpr -deffnm nonequil -dhdl dgdl.xvg -v -nice 0

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GROMACS: gmx mdrun, version 2021.4-Ubuntu-2021.4-2  
Executable: /usr/bin/gmx  
Data prefix: /usr  
Working dir: /home/lynn/ds04/project-sfGFP/alchemical/template\_protein/forward/unequil/frame1  
Command line:  
gmx mdrun -s nonequil.tpr -deffnm nonequil -dhdl dgdl.xvg -v -nice 0

Authorization required, but no authorization protocol specified

Back Off! I just backed up nonequil.log to ./#nonequil.log.1#  
Compiled SIMD: SSE4.1, but for this host/run AVX2\_256 might be better (see  
log).  
Reading file nonequil.tpr, VERSION 2021.4-Ubuntu-2021.4-2 (single precision)  
Changing nstlist from 10 to 100, rlist from 1.2 to 1.2

Using 32 MPI threads  
Using 1 OpenMP thread per tMPI thread

starting mdrun ‘PMX MODEL in water’  
500000 steps, 1000.0 ps.  
step 25400, will finish Sat Jan 20 14:01:21 2024Segmentation fault (core dumped)

Hi, I used mdrun to calculate the free energy after using trjconv extract snapshots. But It shows this error, Anyone have ideas about this error? Thanks!

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**Author:** ![hess](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/hess/32/416_2.png) [@hess](https://gromacs.bioexcel.eu/u/hess)\
**Post date:** [January 22, 2024, 8:46am UTC](https://gromacs.bioexcel.eu/t/mdrun-2024seqmentation-fault/8096/2 "2024-01-22T08:46:13Z")

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My guess is that something is unstable in your setup, but you should never get a segmentation fault. Note that you are not using version 2024 as stated in the title.

Could you try with the latest release, 2023.3, and report if the issue is still present?

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**Author:** ![lynn1](https://avatars.discourse-cdn.com/v4/letter/l/ee59a6/32.png) [@lynn1](https://gromacs.bioexcel.eu/u/lynn1)\
**Post date:** [August 6, 2024, 4:41pm UTC](https://gromacs.bioexcel.eu/t/mdrun-2024seqmentation-fault/8096/3 "2024-08-06T16:41:59Z")

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Thanks very much. it fixed