# Molecules movement during NVT

**URL:** https://gromacs.bioexcel.eu/t/molecules-movement-during-nvt/3574
**Category:** User discussions
**Created:** [January 31, 2022, 8:32pm UTC](https://gromacs.bioexcel.eu/t/molecules-movement-during-nvt/3574 "2022-01-31T20:32:59Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![MOH4](https://avatars.discourse-cdn.com/v4/letter/m/a87d85/32.png) [@MOH4](https://gromacs.bioexcel.eu/u/MOH4)
#### Post date: [January 31, 2022, 8:32pm UTC](https://gromacs.bioexcel.eu/t/molecules-movement-during-nvt/3574/1 "2022-01-31T20:32:59Z")

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Dear all,

During the run for NVT, the system of lipid bilayer in a big box which was not filled with any solvent had changes as the molecules distributed across the box. The system totally ruined and the I did not continue the other steps.

It seemed that the posres.itp were correctly inserted and a vaccum simulation is aimed.

Could you please tell me where the problem can be?

I appreciate your kindness in advance.  
Best