# Protein Ligand complex

**URL:** <https://gromacs.bioexcel.eu/t/protein-ligand-complex/5247>\
**Category:** User discussions\
**Created:** [November 14, 2022, 9:27pm UTC](https://gromacs.bioexcel.eu/t/protein-ligand-complex/5247 "2022-11-14T21:27:30Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![TristanM](https://avatars.discourse-cdn.com/v4/letter/t/e47774/32.png) [@TristanM](https://gromacs.bioexcel.eu/u/TristanM)\
**Post date:** [November 14, 2022, 9:27pm UTC](https://gromacs.bioexcel.eu/t/protein-ligand-complex/5247/1 "2022-11-14T21:27:30Z")

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Hello, I have been trying to prepare a complex that includes ligands of 2 different types, Im unable to combine them due to a directive error. I’m curious how to go about preparing a complex with multiple ligands of different types

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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:** [November 15, 2022, 3:33pm UTC](https://gromacs.bioexcel.eu/t/protein-ligand-complex/5247/2 "2022-11-15T15:33:23Z")

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Please provide the actual error message you received. If both ligands introduce any new parameters into the topology, they need to be grouped and added before any `[moleculetype]` can be defined.