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.