Equivalent stress in indentation

Hello everyone,
I am studying nano-indentation, in which I am interested in calculating the Von Mises stress for each atom in LAMMPS. I have used the following commands.

compute 1 all stress/atom NULL
variable VM atom sqrt(6 (c_1[4]^2+c_1[5]^2+c_1[6]^2)+0.5((c_1[1]-c_1[2])^2+(c_1[2]-c_1[3])^2+(c_1[3]-c_1[1])^2))

for visualisation I used the command
dump 1 all custom 100 dump_txt id type x y z vx vy vz v_VM

I don’t know if the method I’ve applied is correct because when I compare the results obtained, they show higher values than those published in other articles. Thanks a lot for your help.

If you want to know if your syntax is correct, you have to correct your quoting of the input commands. Have a look at it! Does it even look like your input?

If you want to know if your science is correct, you are asking in the wrong forum. This is a forum about using LAMMPS and not about how to do research.

Thank you for your reply.
If I’ve understood correctly, the issue is with the syntax. So I’m going to correct the commands.