[CPMD-list] WAVEFUNCTION OPTIMIZATION

[Veronique Van Speybroeck]

Dear all,

I am studying a system that contains 32 atoms, among which are O, N, P, H,
and use therefore Vanderbilt pseudopotentials.  I'm doing now the initial
optimization of the wavefunction.  How many steps are common for the
initial wavefunction optimization.  I have already done 1500 steps still
the convergence is not reached.  Is this normal.  The total energy does
not systematically decrease.  As an illustration I give the TOTAL ENERGY
quantity for some of the last steps :
(K+E1+L+N+X)           TOTAL ENERGY =         -137.29507284 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29556795 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29535927 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29511531 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29560496 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29543130 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29523925 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29551439 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29553778 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29524706 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29508326 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29423680 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29556416 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29524258 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29297862 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29506422 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29504717 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29551214 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29504128 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29497465 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29156757 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29534837 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29456003 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29543937 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29530715 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29538352 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29561316 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29531235 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29488259 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29496710 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29371573 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29536463 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29503137 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29426423 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29537266 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29501795 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29543533 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29546353 A.U.
 (K+E1+L+N+X)           TOTAL ENERGY =         -137.29495343 A.U.
Does this seem reasonable or is there something wrong?

Thanks to all in advance

Veronique

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Dr. ir. Van Speybroeck Veronique
Laboratorium voor Theoretische Fysica
Universiteit Gent
Proeftuinstraat 86
9000 Gent
Tel +32-9-264.65.58  GSM : +32/474/259767
Fax +32-9-264.65.60
email : veronique.vanspeybroeck at rug.ac.be
http://inwfaxp2.rug.ac.be/~web/onderzoek/proj_3.html
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