[gmx-users] Expansion system after NVT Equilibrium in Gromacs

[yasminesophi at students.itb.ac.id]

i'm currently running a simulation protein in water using gromacs with force field gromos96 54a7. the protein structure that i used is from modeller. there is no problem untill the minimization step but the system is expanding after NVT equilibration. and when i try to do NPT equilibration after that, the system is shrinking [the box volume is smaller than before] 

i'm using the parameter from gromacs tutorial "lysozyme in water" with hbonds constraints for NVT equilibration and the temperature is 298 K. please help me to solve this problem