# Influence of tau\_t, tau\_p values in thermostat, barostat during equilibration

**URL:** <https://gromacs.bioexcel.eu/t/influence-of-tau-t-tau-p-values-in-thermostat-barostat-during-equilibration/4408>\
**Category:** User discussions\
**Tags:** mdp-parameters\
**Created:** [July 4, 2022, 10:16am UTC](https://gromacs.bioexcel.eu/t/influence-of-tau-t-tau-p-values-in-thermostat-barostat-during-equilibration/4408 "2022-07-04T10:16:11Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Kankana](https://avatars.discourse-cdn.com/v4/letter/k/7993a0/32.png) [@Kankana](https://gromacs.bioexcel.eu/u/Kankana)\
**Post date:** [July 4, 2022, 10:16am UTC](https://gromacs.bioexcel.eu/t/influence-of-tau-t-tau-p-values-in-thermostat-barostat-during-equilibration/4408/1 "2022-07-04T10:16:11Z")

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GROMACS version:2020.1  
GROMACS modification: Yes/No  
Here post your question  
How tau\_t, tau\_p values in npt.mdp values can influence the output of the simulation ?I mean how can user define the values for an arbitrary system ? As for e.g: for lysozyme tutorial, for NVT equilibration, tau\_t=0.1 ps was used, in NPT tau\_t=0.1, tau\_p=2 ps were used. How can one determine the values ?