[Pw_forum] UPF file format

[Paolo Giannozzi]

On Apr 9, 2008, at 18:40 , sreekar guddeti wrote:

> One naive question... why is the rab(mesh) != r(mesh + 1) - r(mesh)  
> in the UPF format

rab(i)= dF/dx dx, where r(i), the nonuniform grid used in atomic  
codes, is
defined as r(i) = F(x(i)), with  x(i) a uniform grid spaced dx, F(x)  
a mapping
function. In the "atomic" code, F(x) = r_0 e^x, so rab(i) = r(i) dx.  
The "rab"
grid is useful for the calculation of numerical integrals

Paolo
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Paolo Giannozzi, Dept of Physics, University of Udine
via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222