Abstract
First-principles calculations for KH 2 PO 4 (KDP) show that hydrogen off-center (OC) ordering in the ferroelectric phase is accompanied by electronic charge delocalization from the acceptor and localization at the donor oxygen within the O-H···O bonds. This induces P atoms off-centering in the PO 4 tetrahedrons and pairing with K + ions along the tetragonal axis, thus developing macroscopic polarization. Centered H are collectivelly unstable. However, if the protons are centered, the P and K atoms are stable in their centered positions. In addition, off-centering of a single proton is not energetically favorable. Only correlated proton motions, involving also displacements of heavier atoms, exhibit significant double wells, thus questioning the role of tunneling in isotope effects.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
