# Reference needed for the surface tension coupling scheme used in Gromacs

**URL:** <https://gromacs.bioexcel.eu/t/reference-needed-for-the-surface-tension-coupling-scheme-used-in-gromacs/2875>\
**Category:** User discussions\
**Tags:** mdp-parameters\
**Created:** [September 27, 2021, 4:14pm UTC](https://gromacs.bioexcel.eu/t/reference-needed-for-the-surface-tension-coupling-scheme-used-in-gromacs/2875 "2021-09-27T16:14:43Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![VLCruz](https://avatars.discourse-cdn.com/v4/letter/v/9dc877/32.png) [@VLCruz](https://gromacs.bioexcel.eu/u/VLCruz)\
**Post date:** [September 27, 2021, 4:14pm UTC](https://gromacs.bioexcel.eu/t/reference-needed-for-the-surface-tension-coupling-scheme-used-in-gromacs/2875/1 "2021-09-27T16:14:43Z")

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GROMACS version: any  
GROMACS modification: No  
Dear sirs,  
Can you provide a reference for the surface tension coupling scheme described in the manual ? There is none in the manual itself.

Thanks in advance

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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:** [October 4, 2021, 8:05am UTC](https://gromacs.bioexcel.eu/t/reference-needed-for-the-surface-tension-coupling-scheme-used-in-gromacs/2875/2 "2021-10-04T08:05:32Z")

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I don’t think that there is a GROMACS paper that desribes this. But it is so straightforward that a reference is not really needed. It is the same as anistropic coupling, but then the x and y dimensions are scaled by the same factor, or have the same velocity in PR-coupling, as with isotropic coupling.