# Calculation of pressure in a certain region

Dear friend,

I built a cube (the atomic type B), dug up part of the B atom in the center to form a spherical hole, and filled the spherical hole with another kind of atom A, trying to solve the pressure formed by the A atom in the spherical hole region. However, the pressure calculation results are twice as high as those in the literature. I don’t know what went wrong. The relevant specific instructions are as follows. how to calculate the pressure correctly.if you know, please tell me. Have a good day.
compute stress voidA stress/atom NULL
compute stress1 voidA reduce sum c_stress[1]
compute stress2 voidA reduce sum c_stress[2]
compute stress3 voidA reduce sum c_stress[3]
compute volum voidA voronoi/atom
variable p equal -({c_stress1}+{c_stress2}+\${c_stress3})/（3.0*c_volum[1]）

your input example makes no sense: you compute the sum of the per-atom stress tensor trace, but then divide it by the voronoi cell volume of one particular atom only.

axel.