The parameters characterizing a Morse potential are estimated for a proton bonded with oxygen. The double-minimum potential for the hydrogen bonding in ferroelectric KH2PO4 is constructed by superposing two Morse potential functions. The energy levels...
The parameters characterizing a Morse potential are estimated for a proton bonded with oxygen. The double-minimum potential for the hydrogen bonding in ferroelectric KH2PO4 is constructed by superposing two Morse potential functions. The energy levels are computed by solving onedimensional
Schrodinger equation numerically. The susceptibility is calculated by using linear
response theory and the mean-eld approximation. The two-level system is essential both for KDP and for DKDP, and the static susceptibility is represented by the Barrett equation. The theoretical
phase diagram represents the essential feature of the pressure-temperature phase diagram for KDP and DKDP.