Calculating Pressure - Intro

Hello all!

Now I’m trying to compute the global pressure of a system of atoms.

I’m having some trouble in using compute, variable and print commands.

Could you please help me?

Above is an “slice” of my code:

fix 1 all nvt temp 94.4 94.4 0.1
dump 1 all atom 10 LiqAr3D.lammpstrj
minimize 1.0e-10 1.0e-12 1000 10000
thermo 0
run 100

compute TempAll all temp
compute PresAll all pressure TempAll

variable Pres1 equal c_PressAll
print “Global Pressure (bar) = ${Pres1};”

The log message is: Invalid compute ID in variable formula.

Thank you very very much!

Raph Callef

You can just print the pressure with thermo output, via
the press keyword. Or say

variable p equal press
print "Press = $p"