[lammps-users] NPT density setting

Dear Lammps users,

I want to simulate the elllipsoidal particles using NPT/asphere method.

I will start with a dilute lattice(density=0.02) and low pressure and then increase pressure to 8 over many timesteps. With npt the density will change(because of compress the box).I need/have to reach approximately the density=0.3 because I can see all phase around density 0.4-0.3.

I have as the following input script.

What should I do for it?

Thanks in advance

İnput script:

units lj

atom_style ellipsoid

lattice sc 0.02

region box block 0 16 0 16 0 16

create_box 1 box

create_atoms 1 box

set group all quat/random 982381

mass 1 1.5

shape 1 1 1 3

compute rot all temp/asphere

group spheroid type 1

variable dof equal count(spheroid)+2

compute_modify rot extra ${dof}

velocity all create 2.0 41787 loop geom

pair_style gayberne 1.0 3.0 1.0 4.0

pair_coeff 1 1 1.0 1.0 1.0 1.0 0.2 1.0 1.0 0.2 4.0

neighbor 0.3 bin

timestep 0.002

thermo_style custom step temp etotal vol epair press pe

thermo 100

fix 1 all npt/asphere 2.0 2.0 0.1 xyz 0.0 8.0 0.1

compute_modify 1_temp extra ${dof}

run 50000

unfix 1

fix 2 all npt/asphere 2.0 2.0 0.1 xyz 8.0 8.0 0.1

compute_modify 2_temp extra ${dof}

run 50000