[Pw_forum] pbe with norm conserving pp convergence problem

[Paolo Giannozzi]

On Mon, 2012-09-10 at 17:02 -0400, Peng Chen wrote:

> If I didn't set ecutrho, the default value of ecutrho is 4*ecutwfc. So
> the results are the same as the following, and the energy doesn't
> decrease monotonically. 

it has to. The only reason for which the energy might not decrease
monotonically is the presence of the nonlinear core correction in
pseudpotentials. If you increase even more the cutoff, sooner or later
it has to converge. Note that Ni is a very hard element.

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