# The thermostat coupling term

**URL:** <https://gromacs.bioexcel.eu/t/the-thermostat-coupling-term/6110>\
**Category:** User discussions\
**Created:** [April 4, 2023, 4:35pm UTC](https://gromacs.bioexcel.eu/t/the-thermostat-coupling-term/6110 "2023-04-04T16:35:28Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![Haifa1](https://avatars.discourse-cdn.com/v4/letter/h/f475e1/32.png) [@Haifa1](https://gromacs.bioexcel.eu/u/Haifa1)\
**Post date:** [April 4, 2023, 4:35pm UTC](https://gromacs.bioexcel.eu/t/the-thermostat-coupling-term/6110/1 "2023-04-04T16:35:28Z")

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Is conserved energy include the thermostat coupling term ?

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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 4, 2023, 4:57pm UTC](https://gromacs.bioexcel.eu/t/the-thermostat-coupling-term/6110/2 "2023-04-04T16:57:26Z")

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Yes, otherwise the conserved energy quantity wouldn’t be conserved.

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**Author:** ![Haifa1](https://avatars.discourse-cdn.com/v4/letter/h/f475e1/32.png) [@Haifa1](https://gromacs.bioexcel.eu/u/Haifa1)\
**Post date:** [April 4, 2023, 5:08pm UTC](https://gromacs.bioexcel.eu/t/the-thermostat-coupling-term/6110/3 "2023-04-04T17:08:01Z")

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Thanks a lot for your answer, actually when I used gmx energy to plot conserved energy this what I found:

 ![Screenshot 2023-04-04 at 9.04.46 PM](https://europe1.discourse-cdn.com/flex017/uploads/bioexcel1/original/2X/5/563c55aef330a050ccfa29fdf8d1d4af23ef1c50.png)

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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 4, 2023, 5:28pm UTC](https://gromacs.bioexcel.eu/t/the-thermostat-coupling-term/6110/4 "2023-04-04T17:28:40Z")

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That looks normal. The drift you see is likely due to the finite verlet-buffer-tolerance and the accuracy of the constraint algorithm(s). This is nothing to worry about.

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**Author:** ![Haifa1](https://avatars.discourse-cdn.com/v4/letter/h/f475e1/32.png) [@Haifa1](https://gromacs.bioexcel.eu/u/Haifa1)\
**Post date:** [April 4, 2023, 5:33pm UTC](https://gromacs.bioexcel.eu/t/the-thermostat-coupling-term/6110/5 "2023-04-04T17:33:05Z")

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Thanks a lot hess, I appreciate your help

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**Author:** ![Haifa1](https://avatars.discourse-cdn.com/v4/letter/h/f475e1/32.png) [@Haifa1](https://gromacs.bioexcel.eu/u/Haifa1)\
**Post date:** [April 6, 2023, 6:06am UTC](https://gromacs.bioexcel.eu/t/the-thermostat-coupling-term/6110/6 "2023-04-06T06:06:18Z")

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![NVT](https://europe1.discourse-cdn.com/flex017/uploads/bioexcel1/original/2X/2/2c6b9c2be6d0b7354265e8f775a8627ca7ac0c66.jpeg)  
What about this, the figures represent the following:  
Temperature, Conserved energy, and total energy