[gmx-users] PRESS-XX, PRESS-YY, PRESS-ZZ in .edr file

[Anh Vo]

Hi all,

I have searched online and GROMACS documentation for this question but I
haven't found any clear definition yet. Please help me to clarify it.

In the output .edr file, there are PRESS-XX, PRESS-YY and PRESS-ZZ options.
What do they represent? Are they principal pressures (stresses) averaged for
all atoms during the simulation?
What is the difference between those options and PRESSURE option?

Thank you very much.

Best,
Anh Vo