# Segmentation fault -error

**URL:** <https://gromacs.bioexcel.eu/t/segmentation-fault-error/8496>\
**Category:** User discussions\
**Tags:** mdp-parameters, mdrun, gmx-grompp\
**Created:** [March 3, 2024, 4:04pm UTC](https://gromacs.bioexcel.eu/t/segmentation-fault-error/8496 "2024-03-03T16:04:52Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![IshaChauhan](https://avatars.discourse-cdn.com/v4/letter/i/ac91a4/32.png) [@IshaChauhan](https://gromacs.bioexcel.eu/u/IshaChauhan)\
**Post date:** [March 3, 2024, 4:04pm UTC](https://gromacs.bioexcel.eu/t/segmentation-fault-error/8496/1 "2024-03-03T16:04:52Z")

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GROMACS version: :-) GROMACS - gmx grompp, 2024 (-:

GROMACS modification: Yes/No  
Here post your question

/usr/local/gromacs-2024/bin/gmx grompp -f minim.mdp -c bblcelbox3.gro -p topol.top -o min.tpr  
:-) GROMACS - gmx grompp, 2024 (-:

Executable: /usr/local/gromacs-2024/bin/gmx  
Data prefix: /usr/local/gromacs-2024  
Working dir: /media/isha/Elements/work to be done/bbl\_cel\_n/step1/hpch\_in\_1  
Command line:  
gmx grompp -f minim.mdp -c bblcelbox3.gro -p topol.top -o min.tpr

Ignoring obsolete mdp entry ‘ns\_type’  
Setting the LD random seed to -1154613825

Generated 347361 of the 347361 non-bonded parameter combinations  
Generating 1-4 interactions: fudge = 0.5

Generated 347361 of the 347361 1-4 parameter combinations  
Segmentation fault (core dumped)

My system size is 818382 atoms, the gmx grompp was working fine with an older, however on working with 2022, 2023 and 2024. Can anyone help me out here?

the system configuration i am using is 16core, 16GB, Ubuntu 20.04.6 LTS

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**Author:** ![MagnusL](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/magnusl/32/2380_2.png) [@MagnusL](https://gromacs.bioexcel.eu/u/MagnusL)\
**Post date:** [March 4, 2024, 8:30am UTC](https://gromacs.bioexcel.eu/t/segmentation-fault-error/8496/2 "2024-03-04T08:30:45Z")

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It’s difficult to say what’s the problem. It might be related to [Gmx grompp crashes with a very simple system](https://gromacs.bioexcel.eu/t/gmx-grompp-crashes-with-a-very-simple-system/8399). When you say “… the gmx grompp was working fine with an older, however on working with 2022, 2023 and 2024” could you explain more carefully what you mean? Do you mean “… not working with …”? When you say older, how old?

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**Author:** ![IshaChauhan](https://avatars.discourse-cdn.com/v4/letter/i/ac91a4/32.png) [@IshaChauhan](https://gromacs.bioexcel.eu/u/IshaChauhan)\
**Post date:** [March 4, 2024, 10:03am UTC](https://gromacs.bioexcel.eu/t/segmentation-fault-error/8496/3 "2024-03-04T10:03:24Z")

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gmx grompp was working fine with gromacs version 5.1.4, and the system size i am working with is 8lkh atoms, i have shared the mdp files here  
[minim.mdp](https://gromacs.bioexcel.eu/uploads/short-url/AtKkVQHYpkk71WAFd8ZVjASeHMk.mdp) (1.4 KB)  
[nApt.mdp](https://gromacs.bioexcel.eu/uploads/short-url/sYfcMkFlkV6ySTVqFQ6xyHcfZvK.mdp) (2.9 KB)