# Coordinates don't match with topology

**URL:** <https://gromacs.bioexcel.eu/t/coordinates-dont-match-with-topology/213>\
**Category:** User discussions\
**Created:** [May 29, 2020, 7:36pm UTC](https://gromacs.bioexcel.eu/t/coordinates-dont-match-with-topology/213 "2020-05-29T19:36:13Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![mario](https://avatars.discourse-cdn.com/v4/letter/m/8e7dd6/32.png) [@mario](https://gromacs.bioexcel.eu/u/mario)\
**Post date:** [May 29, 2020, 7:36pm UTC](https://gromacs.bioexcel.eu/t/coordinates-dont-match-with-topology/213/1 "2020-05-29T19:36:13Z")

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GROMACS version:2019.4  
GROMACS modification: No  
Here post your question

Dear Gromacs users.  
I have a problem when i try to add ions to the system for runing a protein molecular dynamics in water:

Fatal error:  
number of coordinates in coordinate file (cbd211\_solv.gro, 59759)  
does not match topology (topol.top, 78898)

Can you help me to solve this problem? I try many actions that i see in research gate but these not resolve.

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**Author:** ![darrenphua](https://avatars.discourse-cdn.com/v4/letter/d/bcef8e/32.png) [@darrenphua](https://gromacs.bioexcel.eu/u/darrenphua)\
**Post date:** [July 13, 2020, 1:58am UTC](https://gromacs.bioexcel.eu/t/coordinates-dont-match-with-topology/213/2 "2020-07-13T01:58:28Z")

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Im facing the same issue with gromacs 2020.3.  
Unable to find what is wrong, and number of solvent added is correct too.

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**Author:** ![jalemkul](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/jalemkul/32/18_2.png) [@jalemkul](https://gromacs.bioexcel.eu/u/jalemkul)\
**Post date:** [July 13, 2020, 2:12am UTC](https://gromacs.bioexcel.eu/t/coordinates-dont-match-with-topology/213/3 "2020-07-13T02:12:27Z")

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You haven’t accurately kept track of everything in your system. The answer to this question is always the same.

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**Author:** ![darrenphua](https://avatars.discourse-cdn.com/v4/letter/d/bcef8e/32.png) [@darrenphua](https://gromacs.bioexcel.eu/u/darrenphua)\
**Post date:** [July 13, 2020, 2:46am UTC](https://gromacs.bioexcel.eu/t/coordinates-dont-match-with-topology/213/4 "2020-07-13T02:46:58Z")

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true…i was doing multiple proteins in solvent. solvent molecules matches, but proteins were still 1 when i had added 6 into the system.

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**Author:** ![neetish](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/neetish/32/341_2.png) [@neetish](https://gromacs.bioexcel.eu/u/neetish)\
**Post date:** [September 2, 2020, 10:46am UTC](https://gromacs.bioexcel.eu/t/coordinates-dont-match-with-topology/213/5 "2020-09-02T10:46:48Z")

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> [@mario](#):
>
> of coordinates in coordinate file (cbd211\_solv.gro, 59759)  
> does not match topology (topol.top, 78898)

Check the topol.top. Have you added the number of molecules for each residue there?

Another silly mistake which I did a few days back was using an all atom co-ordinate file with united atom top file in gromos force filed and I was kept wondering why doesn’t they two match.