[Pw_forum] 'Tetrahedra' and 'scf'

[Eduardo Ariel Menendez Proupin]

Hi,
I think it would be helpful and appreciated to keep scf with tetrahedron
method, at least to make accurate SCF calculations.

It would also be fine if the program just don't calculate the forces when
the tetrahedron methos is chosen, and give a  warning for the beginners
"forces are not variational. Use other smearing method"


> according to changelog-4.2, the tetrahedron method was forbidden to be used
> for scf at *2010-03-25.*
> What is the reason?
>

>forces are not variational, i.e. are not the derivative of the energy.
>This shouldn't be a big problem if you do not calculate forces, though.


Best regards
-- 


Eduardo Menendez
Departamento de Fisica
Facultad de Ciencias
Universidad de Chile
Phone: (56)(2)9787439
URL: http://fisica.ciencias.uchile.cl/~emenendez

They did it!
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