Cluster ab initio calculations of the shape of local potential well and of positions for oxygen atoms in PCN (C=Cd)


Karadag F. , Palaz S., Gungor S. , Mamedov A., Kvyatkovskii O. E.

FERROELECTRICS, cilt.283, ss.61-66, 2003 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 283
  • Basım Tarihi: 2003
  • Doi Numarası: 10.1080/00150190390204132
  • Dergi Adı: FERROELECTRICS
  • Sayfa Sayısı: ss.61-66

Özet

Potential relief and equilibrium positions for oxygen atoms in Cd-O-Nb, Cd-O-Cd and Nb-O-Nb chains are studied in Pb(Cd1/3Nb2/3)O-3 (PCN) and Ba(Cd1/3Nb2/3)O-3 (BCN). Total energy cluster calculations are performed using ab initio restricted Hartree-Fock method. The electron correlation contribution is calculated within Moller-Plesset method. It is revealed that in PCN the oxygen atoms in Cd-O-Cd and Cd-O-Nb chains move in multi-well potentials with four minima shifted transversely to fourfold [001] axis. Whereas the oxygen atom in Nb-O-Nb chain in PCN and all oxygen atoms in BCN move in single-well potentials.