# How to Simulate Ag+ Ions in a gromos54a7 ff

**URL:** <https://gromacs.bioexcel.eu/t/how-to-simulate-ag-ions-in-a-gromos54a7-ff/7978>\
**Category:** User discussions\
**Created:** [January 5, 2024, 3:37am UTC](https://gromacs.bioexcel.eu/t/how-to-simulate-ag-ions-in-a-gromos54a7-ff/7978 "2024-01-05T03:37:03Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![HyewonLee](https://avatars.discourse-cdn.com/v4/letter/h/6a8cbe/32.png) [@HyewonLee](https://gromacs.bioexcel.eu/u/HyewonLee)\
**Post date:** [January 5, 2024, 3:37am UTC](https://gromacs.bioexcel.eu/t/how-to-simulate-ag-ions-in-a-gromos54a7-ff/7978/1 "2024-01-05T03:37:03Z")

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GROMACS version: 23.2  
GROMACS modification: Yes/No

I’m using the **gromos54a7** forcefield. How can I simulate **Ag+ ion** s when the ions.itp file built in the forcefield folder does not have parameters for Ag+ ions?

By any chance, is there any site or paper where I can get the parameter file for the Ag+ ion?