Hi Axel,

use the units metal, here we compare output v_p4 (black line) with c_stressz1 (red line), the compute progress is as follows,

compute strs all stress/atom NULL

compute vol all voronoi/atom

variable stress1 atom “c_strs[1]/10000/c_vol[1]”

variable stress2 atom “c_strs[2]/10000/c_vol[1]”

variable stress3 atom “c_strs[3]/10000/c_vol[1]”

compute stressx1 all reduce ave v_stress1

compute stressy1 all reduce ave v_stress2

compute stressz1 all reduce ave v_stress3

# Store final cell length for strain calculations

variable tmp equal “lx”

variable L0 equal ${tmp}

print “Initial Length, L0: ${L0}”

variable tmp equal “ly”

variable L1 equal ${tmp}

print “Initial Length, L1: ${L1}”

variable tmp equal “lz”

variable L2 equal ${tmp}

print “Initial Length, L2: ${L2}”

Hi Axel,

use the units metal, here we compare output v_p4 (black line) with

c_stressz1 (red line), the compute progress is as follows,

i didn't ask about the value for the units command in your LAMMPS input

script, but the units for the output in your plot! i am surprised that you

are not embarrassed by sending such a plot without proper units and

descriptors to the public and thus showing your disregard for common

scientific practice.

what you have below shows that what you are computing from the pressure

compute is not comparable to what you compute from stress/atom. the output

from compute pressure is the one that is "more correct". the other has an

unphysical weighting included. remember pressure is an "intensive" property.

as i already pointed out, the documentation for compute stress/atom gives

an example how you correctly compute the total pressure from compute

stress/atom. it is trivial to adapt this to getting the individual

components.

axel.