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- W2894474923 abstract "The lattice dynamics of potassium dihydrogen phosphate (KDP) and its deuterated analog DKDP was studied via first-principles DFT calculations. A thorough assessment of the quality of a wide range of functionals supplemented with the approximate inclusion of quantum nuclear effects indicated that the nonlocal van der Waals functional vdW-DF [M. Dion et al., Phys. Rev. Lett. 92, 246401 (2004); J. Klimeifmmode check{s}else v{s}fi{} et al., Phys. Rev. B 83, 195131 (2011)] produces the best agreement with structural data for both compounds. This enabled the calculation of full phonon dispersions in the ferroelectric phase, and hence the phonon density of states and specific heat, in very good agreement with experimental data. Phonon bands and especially modes at the $mathrm{ensuremath{Gamma}}$ point of the Brillouin zone were classified according to their vibrational pattern. This allowed for the assignment of stretching and bending modes of the hydrogen bonds. Internal modes involving the phosphate units were identified at lower frequencies, while the lowest-lying modes were those involving the ${mathrm{K}}^{+}$ ion. These assignments were used to interpret infrared and Raman spectra along the $c$ axis and in the perpendicular plane. Phonon modes calculated at the $mathrm{ensuremath{Gamma}}$ point showed two types of instabilities. One was a normal mode polarized along the $c$ axis of the crystal, while the other corresponded to a twofold-degenerate mode polarized in the perpendicular plane. The former gives rise to a spontaneous polarization in the ferroelectric phase at low temperatures by coupling to an optical ${mathrm{K}}^{+}text{ensuremath{-}}{mathrm{H}}_{2}{mathrm{PO}}_{4}^{ensuremath{-}}$ stretching mode, consistently with a significant off-diagonal Born effective charge on the hydrogen atoms. A mode describing the opposite rotation of neighboring ${mathrm{PO}}_{4}$ tetrahedra was also found to couple strongly to the ferroelectric mode, as this modulates the O-O distance, which determines the barrier for proton transfer. The present study suggests that a minimal model to describe isotope effects in KDP should involve at least three fully coupled vibrational modes." @default.
- W2894474923 created "2018-10-05" @default.
- W2894474923 creator A5004059767 @default.
- W2894474923 creator A5020807074 @default.
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- W2894474923 date "2018-09-28" @default.
- W2894474923 modified "2023-10-06" @default.
- W2894474923 title "<i>Ab initio</i> study of the structure, isotope effects, and vibrational properties in KDP crystals" @default.
- W2894474923 cites W116239404 @default.
- W2894474923 cites W11913443 @default.
- W2894474923 cites W1480344782 @default.
- W2894474923 cites W1537373346 @default.
- W2894474923 cites W1550186202 @default.
- W2894474923 cites W1649134563 @default.
- W2894474923 cites W1721994407 @default.
- W2894474923 cites W1758520278 @default.
- W2894474923 cites W1810694562 @default.
- W2894474923 cites W1964595713 @default.
- W2894474923 cites W1964791324 @default.
- W2894474923 cites W1965286684 @default.
- W2894474923 cites W1965489498 @default.
- W2894474923 cites W1968755006 @default.
- W2894474923 cites W1977063671 @default.
- W2894474923 cites W1978756048 @default.
- W2894474923 cites W1981105727 @default.
- W2894474923 cites W1981368803 @default.
- W2894474923 cites W1981619846 @default.
- W2894474923 cites W1982952953 @default.
- W2894474923 cites W1984821796 @default.
- W2894474923 cites W1985641134 @default.
- W2894474923 cites W1988115197 @default.
- W2894474923 cites W1988320534 @default.
- W2894474923 cites W1988636443 @default.
- W2894474923 cites W1989060947 @default.
- W2894474923 cites W1992054974 @default.
- W2894474923 cites W1993239394 @default.
- W2894474923 cites W1993731908 @default.
- W2894474923 cites W1995246296 @default.
- W2894474923 cites W1996620291 @default.
- W2894474923 cites W2000536749 @default.
- W2894474923 cites W2003193361 @default.
- W2894474923 cites W2003443675 @default.
- W2894474923 cites W2007395042 @default.
- W2894474923 cites W2008423326 @default.
- W2894474923 cites W2008997102 @default.
- W2894474923 cites W2011254994 @default.
- W2894474923 cites W2014137426 @default.
- W2894474923 cites W2014166972 @default.
- W2894474923 cites W2014548724 @default.
- W2894474923 cites W2016882476 @default.
- W2894474923 cites W2018900902 @default.
- W2894474923 cites W2020089207 @default.
- W2894474923 cites W2020320444 @default.
- W2894474923 cites W2021119317 @default.
- W2894474923 cites W2022106131 @default.
- W2894474923 cites W2023769566 @default.
- W2894474923 cites W2025066370 @default.
- W2894474923 cites W2030601089 @default.
- W2894474923 cites W2039463459 @default.
- W2894474923 cites W2040083878 @default.
- W2894474923 cites W2040999842 @default.
- W2894474923 cites W2044591029 @default.
- W2894474923 cites W2044774429 @default.
- W2894474923 cites W2045596260 @default.
- W2894474923 cites W2047826444 @default.
- W2894474923 cites W2048259027 @default.
- W2894474923 cites W2054089272 @default.
- W2894474923 cites W2054813781 @default.
- W2894474923 cites W2055070192 @default.
- W2894474923 cites W2056304260 @default.
- W2894474923 cites W2057852235 @default.
- W2894474923 cites W2058858234 @default.
- W2894474923 cites W2059885388 @default.
- W2894474923 cites W2064129244 @default.
- W2894474923 cites W2065684255 @default.
- W2894474923 cites W2066235476 @default.
- W2894474923 cites W2066966625 @default.
- W2894474923 cites W2067340945 @default.
- W2894474923 cites W2069736009 @default.
- W2894474923 cites W2072113974 @default.
- W2894474923 cites W2072540283 @default.
- W2894474923 cites W2075912261 @default.
- W2894474923 cites W2075961089 @default.
- W2894474923 cites W2076462975 @default.
- W2894474923 cites W2078085994 @default.
- W2894474923 cites W2080073655 @default.
- W2894474923 cites W2082545972 @default.
- W2894474923 cites W2083222334 @default.
- W2894474923 cites W2085093563 @default.
- W2894474923 cites W2087414392 @default.
- W2894474923 cites W2088572784 @default.
- W2894474923 cites W2093880330 @default.
- W2894474923 cites W2098045717 @default.
- W2894474923 cites W2127378318 @default.
- W2894474923 cites W2150697053 @default.