Dear all,

I'm attempting to run NVT on water the molecules evaporate and leave the simulation cell. Please notice the images below displaying frame 1 and last frame along with the MD paramters.

Much appreciated. 

--- Dynamics parameters ----

Ensemble : NVT
Temperature : 298.00 K
Control method : Nose
Q ratio : 0.0100000
Timestep : 1.00 fs
Number of steps : 1000000
Duration : 1000 ps
Initial velocities : Random
Random number seed : 1643259833

---- Energy parameters ----

Forcefield : COMPASSIII (Version 1.1)
Charges : Forcefield assigned
Electrostatic terms:
Summation method : Ewald
Accuracy : 0.0001 kcal/mol
Buffer width : 0.5 A

van der Waals terms:
Summation method : Atom based
Truncation method : Cubic spline
Cutoff distance : 15.5 A
Spline width : 1 A
Long range correction : YES
Buffer width : 0.5 A

---- Thermostat ----

Nose mass parameter, Q mass: 5.31192 kcal/mol*ps^2

Using multiple time step dynamics. Long time step : 4 short steps

---- Dynamics summary ----

Initial Final Average Std. Dev.
------- ----- ------- ---------
Tot. energy (kcal/mol) 326.670 -583.484 -556.140 22.986
Pot. energy (kcal/mol) 61.074 -846.715 -821.737 17.379
Kin. energy (kcal/mol) 265.596 263.231 265.597 13.362
Tot. enthalpy (kcal/mol) -1319.619 -585.471 -529.148 129.138
Temperature (K) 298.000 295.347 298.001 14.992
Pressure (GPa) -3.824 -0.005 0.063 0.293
Volume (A^3) 2991.461 2991.461 2991.461 0.000
Density (g/cm^3) 1.000 1.000 1.000 0.000