Dear all,
In a metallic system, using NPT I set pressure in x direction and zero pressure in the other two (y and z) directions as follows:
fix ffix all npt temp \{temperature\} {temperature} 0.1 x 100.0 100.0 1.0 y 0.0 0.0 1.0 z 0.0 0.0 1.0
Surprisingly I got average pressure around 33 (bar) in each direction. Is there something wrong in my setting? A complete input file is below:
units metal
boundary p p p
atom_style atomic
read_restart restart.*
pair_style eam/fs
pair_coeff * * \{home\}/code/lammps/lammps\-15Jan11/potentials/Cu\-Zr\_2\.eam\.fs Cu Zr
fix fpressure all ave/time 100 10 1000 c\_thermo\_press file pressure\.lmp mode vector ave one
thermo 1000
thermo\_style custom step temp pe etotal vol press
timestep 0\.001
dump dumptrj all atom 100000 trj\.lammpstrj
dump\_modify dumptrj scale no sort id append yes
restart 1000000 restart \# write restart file every steps
variable temperature equal 1340\.0
fix ffix all npt temp {temperature} ${temperature} 0.1 x 100.0 100.0 1.0 y 0.0 0.0 1.0 z 0.0 0.0 1.0
run 4000000 # temperature increase 0.5 K/ps
Thanks a lot.
Eugene