# Atomtype CR not found

**URL:** <https://gromacs.bioexcel.eu/t/atomtype-cr-not-found/3563>\
**Category:** User discussions\
**Tags:** forcefield, analysis-tools\
**Created:** [January 28, 2022, 10:40am UTC](https://gromacs.bioexcel.eu/t/atomtype-cr-not-found/3563 "2022-01-28T10:40:33Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Abhimanyuchauhan](https://avatars.discourse-cdn.com/v4/letter/a/977dab/32.png) [@Abhimanyuchauhan](https://gromacs.bioexcel.eu/u/Abhimanyuchauhan)\
**Post date:** [January 28, 2022, 10:40am UTC](https://gromacs.bioexcel.eu/t/atomtype-cr-not-found/3563/1 "2022-01-28T10:40:33Z")

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hello all,  
i have generated the ligand topology file from swissparam, during the step addition of ions. I got error  
ERROR 1 [file LIG.itp, line 23]:  
Atomtype CR not found

There was 1 note

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Program: gmx grompp, version 2020.1-Ubuntu-2020.1-1  
Source file: src/gromacs/gmxpreprocess/toppush.cpp (line 1408)

Fatal error:  
There was 1 error in input file(s)  
can any one suggest me how to solve this error  
thanks

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**Author:** ![alevilla](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/alevilla/32/439_2.png) [@alevilla](https://gromacs.bioexcel.eu/u/alevilla)\
**Post date:** [February 3, 2022, 9:33am UTC](https://gromacs.bioexcel.eu/t/atomtype-cr-not-found/3563/2 "2022-02-03T09:33:00Z")

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Hi,  
You can check if the atoms CR and the corresponding parameters are defined in the LIG.itp file or/and in the forcefield files that are included in the topology files.  
I also recall that others discussed a similar issue in this forum, maybe you can find their posts useful.  
Best regards  
Alessandra