# Reimplementing user/table potential feature

**URL:** <https://gromacs.bioexcel.eu/t/reimplementing-user-table-potential-feature/6266>\
**Category:** User discussions\
**Tags:** forcefield\
**Created:** [April 24, 2023, 4:44pm UTC](https://gromacs.bioexcel.eu/t/reimplementing-user-table-potential-feature/6266 "2023-04-24T16:44:29Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![jmcdaniel43](https://avatars.discourse-cdn.com/v4/letter/j/77aa72/32.png) [@jmcdaniel43](https://gromacs.bioexcel.eu/u/jmcdaniel43)\
**Post date:** [April 24, 2023, 4:44pm UTC](https://gromacs.bioexcel.eu/t/reimplementing-user-table-potential-feature/6266/1 "2023-04-24T16:44:29Z")

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GROMACS version:  
GROMACS modification: Yes/No  
Here post your question  
Dear Gromacs team:

I am wondering if there are plans to reimplement support for user/table potentials. To my knowledge, support for this feature ended after Gromacs 5.0, and while it appears there were plans to reimplement this feature ([User-Defined Potentials with Verlet Neighbor Searching](https://gromacs.bioexcel.eu/t/user-defined-potentials-with-verlet-neighbor-searching/1702)), it seems to me it hasn’t been done yet.

We develop custom force fields that are neither LJ or Buckingham form, and in the past I’ve used table functions to do simulations in Gromacs with these force fields (e.g. [https://pubs.acs.org/doi/full/10.1021/acs.jpcb.6b05328](https://pubs.acs.org/doi/full/10.1021/acs.jpcb.6b05328)). But I haven’t been able to use Gromacs for this in several years do to the dropped user/table potential feature.

thanks very much,  
Jesse

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**Author:** ![hess](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/hess/32/416_2.png) [@hess](https://gromacs.bioexcel.eu/u/hess)\
**Post date:** [April 25, 2023, 6:27am UTC](https://gromacs.bioexcel.eu/t/reimplementing-user-table-potential-feature/6266/2 "2023-04-25T06:27:55Z")

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We realize that many users need this feature. This is planned for every release. But do to a lack of resources we have, unfortunately, not been able to reimplement this yet.

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**Author:** ![mabraham](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/mabraham/32/33_2.png) [@mabraham](https://gromacs.bioexcel.eu/u/mabraham)\
**Post date:** [April 25, 2023, 7:06am UTC](https://gromacs.bioexcel.eu/t/reimplementing-user-table-potential-feature/6266/3 "2023-04-25T07:06:05Z")

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Note that older GROMACS versions still work, so you aren’t blocked from using GROMACS generally, unless you also need capabilities that GROMACS acquired subsequently!

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**Author:** ![jmcdaniel43](https://avatars.discourse-cdn.com/v4/letter/j/77aa72/32.png) [@jmcdaniel43](https://gromacs.bioexcel.eu/u/jmcdaniel43)\
**Post date:** [April 25, 2023, 1:00pm UTC](https://gromacs.bioexcel.eu/t/reimplementing-user-table-potential-feature/6266/4 "2023-04-25T13:00:23Z")

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Thanks for the responses. Yes I will continue to use an older version for now, and glad to hear this is still being planned for upcoming releases