Hi all,
I am new to LAMMPS and i am trying to perform to biaxial molecules on higher density.
In the output listed while perform, i found that the pressure is having a negative value.
I tried to perform only NVT simulations the pressure term displays a negative value.
Could you please kindly let me know why is it. Herewith i have attached my input script.
Kindly let me know what can i do.
variable T equal 2.8
variable P equal 1.20
variable rho equal 0.30
# ------------------------------------------------------------------------------
# ----------- GayBerne ellipsoids in a 3D -------------------------------
# ------------------------------------------------------------------------------
units lj
atom_style ellipsoid
dimension 3
boundary p p p
lattice sc ${rho}
region box block 0 10 0 10 0 10
create_box 1 box
create_atoms 1 box
set type 1 mass 1.0
set type 1 shape 1.4 0.714 3.0
#set group all quat/random 123456782
set type 1 quat 0.892 0.09 0.095 0.367
variable gb_ps_gamma equal 1.0
variable gb_ps_upsilon equal 3.0
variable gb_ps_mu equal 1.0
variable gb_ps_cutoff equal 4.0
pair_style gayberne ${gb_ps_gamma} ${gb_ps_upsilon} ${gb_ps_mu} ${gb_ps_cutoff}
variable gb_pc_epsilon equal 1.0
variable gb_pc_sigma equal 0.714
variable gb_pc_epsilon_i_a equal 1.7
variable gb_pc_epsilon_i_b equal 1.2
variable gb_pc_epsilon_i_c equal 0.2
variable gb_pc_epsilon_j_a equal 1.7
variable gb_pc_epsilon_j_b equal 1.2
variable gb_pc_epsilon_j_c equal 0.2
variable gb_pc_cutoff equal 4.0
pair_coeff * * ${gb_pc_epsilon} ${gb_pc_sigma} &
${gb_pc_epsilon_i_a} ${gb_pc_epsilon_i_b} ${gb_pc_epsilon_i_c} &
${gb_pc_epsilon_j_a} ${gb_pc_epsilon_j_b} ${gb_pc_epsilon_j_c} ${gb_pc_cutoff}