The POTCAR file contains now more information about the pseudopotential generation. With the new POTCAR files it is no longer necessary to specify valence and mass in the INCAR file. If tags exist in the INCAR file they are checked against the parameters found on the POTCAR file and error messages are printed.
The new POTCAR file also contains a default cutoff (ENCUT), therefore it is no longer required to specify ENCUT in the INCAR file. Of course the value in the INCAR file overwrites the default in the POTCAR file. For POTCAR files with more than one species the maximum value found in the POTCAR file is used for the calculation (section 5.4,13.3).
In addition the POTCAR file contains now information about the approximate error according to the RRKJ kinetic energy criterion. This approximate error is taken into account when cohesive energies are calculated, and because of this it is no longer the case that the cohesive energy decreases strictly with the energy cutoff. If you do not like this feature remove the lines after
Error from kinetic energy argument (eV)till (but not including) the line
END of PSCTR-control parametersin the POTCAR file. We want to point out, that the RRKJ kinetic energy is usually very accurate and corrects for more than of the errors in the cohesive energy, but it works only if there is not a considerable charge transfer (or promotion) from one state to another state (s d or s p).