Fixed bug in virial and stress computation to account for molecules in the system.
Fixed bug in virial and stress computation to account for molecules in the system.

g-bauer/lumol,antoinewdg/lumol,g-bauer/lumol,g-bauer/lumol,antoinewdg/lumol,Luthaf/cymbalum,Luthaf/cymbalum,antoinewdg/lumol