[CPMD-list] External Potential keyword

[Salomon Billeter]

Hi,

NR1S, NR2S, and NR3S are the dimensions of the real space mesh (X, Y, Z).
They are determined from the plane-wave cutoff and the system size to fit
the requirements of FFT. You'll find them in the section SUPERCELL of the
CPMD output. Note that NR1 is the number of points along X used in one
parallel process only, so the dimension you'll want to give to your
extpot.unfo.grid is NR1S*NR2S*NR3S rather than NR1*NR2S*NR3S.

Note also that the ordering of the elements is different from the Fortran
convention, i.e. the fastest cycling dimesion is the last one rather than
the first one. In the unformatted case, each record will contain the values
for every point Z of a given XY-plane.

Best regards,
Salomon