Dear Siesta users,
I noticed that when communicating with a Master code, e.g. via i-PI
socket, the values that would be sent to a socket are
the forces and the _total_ energy, not the _free_ energy, even though I
use Fermi-Dirac smearing.
At the same time, in the manual I read: "We finally note that, in both
cases (Fermi-Dirac and Methfessel-Paxton), once a finite temperature has
been chosen, the relevant energy is not the Kohn-Sham energy, but the
Free energy. In particular, the atomic forces are derivatives of the
Free energy, not the KS energy."
This means, to my understanding, that a client code receives an energy
and forces that are inconsistent to each other, and the energy is
somewhat ill-defined. Do you know why such choice was made? Is there any
problem with sending the free energy?
Many thanks,
Karen Fidanyan
PhD student
Max Planck Institute for the Structure and Dynamics of Matter
Hamburg, Germany
--
SIESTA is supported by the Spanish Research Agency (AEI) and by the European
H2020 MaX Centre of Excellence (http://www.max-centre.eu/)
