<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">Dear all,<br><br>We have an enquiry about some results appearing in the output file of the <span style="font-weight: bold;">pw.x</span> run.<br><br>We
are trying to perform computations on isolated atoms to try to get a
significance of the results given by the code. We have to recall that we
are new users of QE. And as far as we know it is not too much indicated
for such kind of computations but it is rather a first try to get some
understanding on the "behaviour" of the code.<br><br>So the problem is
that when performing the computations on He for example we obtain the
correct ground state energy up to the Hartree-Fock limit. But when
applied to other atoms (Li, Na, Be, C, ...) the value obtained do not
correspond at all to the known value.<br><br>We thus have 2
questions:<br><br>1- Why is it that the level of refinement obtained is
the Hartree-Fock limit; we may have expected a better accuracy? Is it
linked to the use of pseudo-potentials?<br>2- What can we do to recover the correct (up to the Hartree-Fock limit at least) total energy for the other atoms? <br><div> <br>Sincerely Yours,<br>On behalf of the <br>Groupe de Structure et Dynamique des Atomes et Molecules<br>Laboratoire de Physique Fondamentale<br>Département de Physique<br>Université de Douala.<br><br></div>Steve.</td></tr></table><br>