# Error in solvation

**URL:** <https://gromacs.bioexcel.eu/t/error-in-solvation/9298>\
**Category:** User discussions\
**Tags:** simulation-setup\
**Created:** [June 4, 2024, 11:07am UTC](https://gromacs.bioexcel.eu/t/error-in-solvation/9298 "2024-06-04T11:07:43Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Ranbir720](https://avatars.discourse-cdn.com/v4/letter/r/e495f1/32.png) [@Ranbir720](https://gromacs.bioexcel.eu/u/Ranbir720)\
**Post date:** [June 4, 2024, 11:07am UTC](https://gromacs.bioexcel.eu/t/error-in-solvation/9298/1 "2024-06-04T11:07:43Z")

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GROMACS version:  
GROMACS modification: Yes/No  
Here post your question

While performing solvation step , gmx solvate adds 8134 water molecules. But when I saw my solv.gro file , it has added water molecules vaguely starting from the ligand coordinates. And when I run addition of ions step . The fatal error arises and reads that the water molecules in the topology.top file and the solv.gro don’t match . I thought that it might be due to the reason that my ligand residue has been named 1LIG and the software adds water directly from 2SOL hence the error . I tried renaming the ligand residue but to no avail. Please help me in this regard

 ![17175013646506167902518021750730](https://europe1.discourse-cdn.com/flex017/uploads/bioexcel1/original/2X/2/269380acbcf81c8c2678133bb0ecdc9fdcf4f27b.jpeg)

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**Author:** ![Seyilaxa](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/seyilaxa/32/3136_2.png) [@Seyilaxa](https://gromacs.bioexcel.eu/u/Seyilaxa)\
**Post date:** [June 4, 2024, 5:07pm UTC](https://gromacs.bioexcel.eu/t/error-in-solvation/9298/2 "2024-06-04T17:07:15Z")

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`gmx solvate` should not affect the original part of .gro file. Have you try to check what’s the missing 86 atoms in the .gro file generated in the previous step?

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**Author:** ![Ranbir720](https://avatars.discourse-cdn.com/v4/letter/r/e495f1/32.png) [@Ranbir720](https://gromacs.bioexcel.eu/u/Ranbir720)\
**Post date:** [June 5, 2024, 5:07am UTC](https://gromacs.bioexcel.eu/t/error-in-solvation/9298/3 "2024-06-05T05:07:56Z")

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Thank you so much for your response. The problem got solved . Actually the name of the molecule in the molecule type section of topology file was mentioned as LIG 3 . So when I removed this 3 the problem got solved and there was no error observed . It seems this 3 was creating a confusion and an error