Vibrational modes of hydrogens in the proton ordered phase XI of ice: Raman spectra above 400 cm−1

Abstract

Polarized Raman spectra of the proton ordered phase of ice Ih, i.e., ice XI, were measured above 400 cm(-1) in the range of librational, bending, and stretching vibrations. Vibrational modes in ice XI, of which symmetry is C(2v) (12)(Cmc2(1)), were discussed from the group theoretical point of view. In the librational mode spectra below 1200 cm(-1), several new peaks and clear polarization dependencies were observed. Assignments of the librational modes agree reasonably well with the recent MD calculations by Iwano et al. (J. Phys. Soc. Jpn. 79, 063601 (2010)). In contrast, the spectra for bands above 1200 cm(-1) show no distinct polarization dependencies and the spectra resemble those in ice Ih. In ice XI, however, fine structure composed of several weak peaks appear on the broad bending and the combination band. No direct evidence of the LO-TO splitting of the ν(3) anti-symmetric stretching mode was obtained. It is contrary to the case of the translational modes Abe and Shigenari (J. Chem. Phys. 134, 104506 (2011)). Present results suggest that the influence of the proton ordering in ice XI is weaker than the effect of inter- and intra-molecular couplings in the stretching vibrations of ice Ih.

Raman and IR Spectra of Ice Ih and Ice XI with an Assessment of DFT Methods

“…The IR and Raman spectra of ice Ih and XI are calculated and compared. The librational vibrations are found to be the most affected by the proton ordering from the comparison of both the IR and Raman spectra between ice Ih and XI, in agreement with the measurements by Shigenari and Abe 32 . This can be used as a spectroscopic fingerprint of ice XI to distinguish ferroelectric ice XI from ice Ih.…”

“…[24][25][26][27][28][29] Only a few works on ice XI have been carried out until now. [30][31][32][33][34][35] The polarized Raman spectra of ice XI have been measured based on samples obtained from KOH-doped ice and the vibrational modes in the translational, librational, bending, and stretching region have been assigned by Abe and Shigenari. [31][32] Comparisons between the spectra of ice Ih and ice XI have been presented in the regions of translational and librational vibrations.…”

“…[30][31][32][33][34][35] The polarized Raman spectra of ice XI have been measured based on samples obtained from KOH-doped ice and the vibrational modes in the translational, librational, bending, and stretching region have been assigned by Abe and Shigenari. [31][32] Comparisons between the spectra of ice Ih and ice XI have been presented in the regions of translational and librational vibrations. 30,34 The differences between IR spectra of ice Ih and ice XI and the increase of absorbance over a wide frequency range was discussed by Abe and Shigenari.…”

Ab initio investigation of electronic and vibrational contributions to linear and nonlinear dielectric properties of ice

“…In a recent article, Shigenari and Abe 49 pointed out that, while stretching (and other) vibrational frequencies above 1200 cm −1 vary insignificantly from ice Ih to ice XI, there are notable differences in the librational modes between 600 and 1100 cm −1 . This observation is consistent with the B3LYP/tzp(pol) IR spectra that we have calculated for P, BF, and ice XI structures.…”

Properties of Ferroelectric Ice

“…Features of the infrared and vibrational spectrum of ice XI became better known due to recent studies [15,16]. Especially important is the region of the librational motions of water molecules, presented because there is a uniquely large difference in the spectra in this region between ice XI and ice Ih.…”