# Gmx mdrun -deffnm NVT

**URL:** <https://gromacs.bioexcel.eu/t/gmx-mdrun-deffnm-nvt/7862>\
**Category:** User discussions\
**Created:** [December 14, 2023, 11:02am UTC](https://gromacs.bioexcel.eu/t/gmx-mdrun-deffnm-nvt/7862 "2023-12-14T11:02:10Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![sayan23us](https://avatars.discourse-cdn.com/v4/letter/s/65b543/32.png) [@sayan23us](https://gromacs.bioexcel.eu/u/sayan23us)\
**Post date:** [December 14, 2023, 11:02am UTC](https://gromacs.bioexcel.eu/t/gmx-mdrun-deffnm-nvt/7862/1 "2023-12-14T11:02:11Z")

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GROMACS version:2018.1  
GROMACS modification: No  
I am getting the below error when I giving the command “gmx mdrun -deffnm NVT”

Too many LINCS warnings (1000)  
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

I have used ATB to build topology

 ![Screenshot from 2023-12-14 16-26-35](https://europe1.discourse-cdn.com/flex017/uploads/bioexcel1/original/2X/f/f46a0cea71652845e7996c7d018b0cf5f1a0a3cf.png)

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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:** [December 14, 2023, 11:09am UTC](https://gromacs.bioexcel.eu/t/gmx-mdrun-deffnm-nvt/7862/2 "2023-12-14T11:09:28Z")

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Have you run proper energy minimization beforehand?