The PSCTR file controls the pseudopotential generation program (rhfsps) and the calculation of the US pseudopotentials (fourpot3). A simple PSCTR file might have the following contents:
TITEL = Pd: NC=2.0 US=2.7, real-space 200eV, opt LULTRA = T use ultrasoft PP ? RWIGS = 2.600 Wigner-Seitz radius ICORE = 0 local potential RMAX = 3.000 core radius for proj-oper QCUT = 4.000; QGAM = 8.000 optimization parameters Description l E TYP RCUT TYP RCUT 0 .000 15 2.100 15 2.100 2 .000 7 2.000 23 2.700 2 -.600 7 2.000 23 2.700 1 .000 7 2.700 7 2.700Different Pseudopotentials can be generated:
and variants 
The PSCTR file is a tagged format free-ASCII file (similar to INCAR, section 6): Each line consists of a tag (i.e. a string) the equation sign '=' and a number of values. It is possible to give several parameter-value pairs ( tag = values ) on a single line, if each of these pairs are separated by a semicolon ';'. If a line ends with a backlash the next line is a continuation line. Comments are normally preceded by the number sign '#', but in most cases comments can be append to a parameter-value pair without the '#'. In this case semicolons should be avoided within the comment.
A lot of information is passed via the POTCAR file from the pseudopotential generation package to VASP/VAMP. Among the most important information is the default energy cutoff (see section 11.3.