[Pw_forum] differences in vdW_kernel_table

[Paolo Giannozzi]

On Thu, 2012-08-23 at 18:34 +0200, Eduardo Ariel Menendez Proupin wrote:

> I generated the file vdW_kernel_table with version 5.0.1 and it is different
>  from the file coming with the 4.3.2. Should they be different ?

they shouldn't, but apparently the kernel is given by an integral that
is numerically unstable at small values of q, so you may get slightly
different numbers with different machines/compilers/phases of the moon.
This shouldn't however affect the final results: those large numbers 
you get are multiplied by very small densities. 

P.
-- 
Paolo Giannozzi, IOM-Democritos and University of Udine, Italy