[CPMD-list] grid on real space

[Zhenyu LI]

Dear Juerg,

Thanks. So in this situation, the inner production of two real space
functions can not be calculated by add all number form 1 to NNR1
directly, and it should be something like
SUM=0.d0
DO K = 1, NR3
  DO J = 1, NR2
     DO I = 1, NR1
         N = I + (J-1)*KR1+(K-1)*KR1*KR2
         SUM=SUM+F1(N)*F2(N)
     END DO
 END DO
END DO

right?

best wishes,
zhenyu



On Mon, 28 Mar 2005 18:01:33 +0200 (MEST), Juerg Hutter
<hutter at pci.unizh.ch> wrote:
> Hi
> 
> KR1, KR2, KR3 are the dimensions of Fortran arrays
> that are used to keep the real space grid values.
> The grid size is actually NR1, NR2, NR3.
> For performance reasons (memory access) it is a good idea
> to choose KR1 = NR1+1.
> You can think of KR1 as the leading dimension parameter
> you can find e.g. in LAPACK.
> 
> regards
> 
> Juerg Hutter
> 
> ----------------------------------------------------------
> Juerg Hutter                   Phone : ++41 1 635 4491
> Physical Chemistry Institute   FAX   : ++41 1 635 6838
> University of Zurich           E-mail: hutter at pci.unizh.ch
> Winterthurerstrasse 190
> CH-8057 Zurich, Switzerland
> ----------------------------------------------------------
> 
> 
> On Mon, 28 Mar 2005, Zhenyu LI wrote:
> 
> > Dear all,
> >
> > I am a liitle confused on the grid on real space. We found that
> > MAXFFT=NNR1=KR1*KR2*KR3.
> > So we expect a grid from 0 to KR1-1, or from 1 to KR1. According to
> > PBC, in both case f(0)=f(KR1). But the real space wavefunction seems
> > normalized to 1/Sqrt(NR1*NR2*NR3) instead of 1/Sqrt(KR!*KR2*KR3), and
> > typically KR1=NR1+1.
> >
> > Would anybody please clarify this issue for me, thanks!
> >
> > best wishes,
> > zhenyu
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>