Dear Sir,

I am using press/berendsen barostat.

As mentioned in the document this fix does NOT perform time integration. Thus you must use a separate time integration fix, like fix nve or fix nvt to actually update the positions and velocities of atoms.

So, I am using this command

fix 1 all press/berendsen iso 1 1 1000

fix 2 all nvt temp 300 300 100

but in output, I am getting nan values

Step Temp Density Press

0 300 1.3333408 1756.5831

1000 -nan -nan -nan

2000 -nan -nan -nan

3000 -nan -nan -nan

4000 -nan -nan -nan

5000 -nan -nan -nan

6000 -nan -nan -nan

7000 -nan -nan -nan

8000 -nan -nan -nan

9000 -nan -nan -nan

10000 -nan -nan -nan

Please suggest where I am doing mistake.