Compute Stress n2p2/lammps interface

[Matheus-Novoa]

I reported in this issue (#170 ), problems with some lammps "computes" related to stress calculations.

Recently, i read this paper (https://aip.scitation.org/doi/10.1063/1.3553717) that show, step by step, the stress calculation algorithm.

Is this algorithm similar to the default lammps algorithm when a conventional potential is used? Does this algorithm influence in which lammps commands to use to compute stress?

For more details about my issue, see in #170.

Thaks in advance.