[CPMD-list] Diffrent energy results

[Juerg Hutter]

Hi

some general remarks on comparing energies:
1) Converge the wavefunction very well 10^-6 or better
2) Make sure that all parameters are the same
   - same geometry, functional
   - same number of grid points (this may differ
     if you use different FFT libraries)
   - same number of spline points for the PP
     IMPORTANT: the default has changed from 3.5 to 3.7!
     old value 500, new value 3000
     you can set this with
     SPLINE POINTS
        3000
3) A very good test is to start always from the same
   RESTART file and only do one single step. This
   way ALL energies have to be exactly the same and
   no problems with different convergence rates occure.


A special remark concerning your numbers:
all your outputs show different numbers for the ESR
energy. This is the simple sum of the pair energy
from the Ewald sum and depends only on the geometry.