I have added the option to Tochnog to calculate and save the correct value of the equivalent Von Mises Stress.
to do that you use the command
post_calcul -materi_stress -mises
I have posted the modified code so that it can be build with that option, and placed a copy of the OSX built code. I named the file "tochnogLP" to imply: built to use the Lapack Solver.
Good luck and enjoy!