# Regarding missing atomtypes in oplsaa

**URL:** <https://gromacs.bioexcel.eu/t/regarding-missing-atomtypes-in-oplsaa/11875>\
**Category:** User discussions\
**Created:** [April 6, 2025, 9:59am UTC](https://gromacs.bioexcel.eu/t/regarding-missing-atomtypes-in-oplsaa/11875 "2025-04-06T09:59:18Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![bishal](https://avatars.discourse-cdn.com/v4/letter/b/a698b9/32.png) [@bishal](https://gromacs.bioexcel.eu/u/bishal)\
**Post date:** [April 6, 2025, 9:59am UTC](https://gromacs.bioexcel.eu/t/regarding-missing-atomtypes-in-oplsaa/11875/1 "2025-04-06T09:59:19Z")

</div>

GROMACS version:  
GROMACS modification: Yes/No  
I am planning to perform molecular simulation in certain drugs which has thiazine in it and i couldnot find thiazine in atomtypes.atp so couldnot make rtp files