PSTRESS
PSTRESS = [real]
Description: This flag controls whether Pulay corrections are added to the stress tensor or not.
If the PSTRESS tag is specified VASP will add this stress to the stress tensor, and an energy [math]\displaystyle{ E= V * \mathrm{PSTRESS} }[/math] to the energy. This allows the user to converge to a specified external pressure.