Structure and dynamics of the Lu2Si2O7 lattice: Ab initio calculation

Raman spectrum of oxyorthosilicate Lu2SiO5: Ab initio calculation

“…Table shows the results of our calculation of wavenumbers of the vibrations active in the Raman spectrum and comparison with experiment. The data were obtained using the WC1LYP hybrid functional, which we used to calculate the spectrum of lutetium pyrosilicate . Nonpolarized Raman spectrum was calculated (Figure ) in a good agreement with experiment.…”

“…Together with the use of hybrid density functional theory functionals, as well as the ability to take into account correlations, CRYSTAl14 is a good tool for calculating the vibrational spectra of insulator materials with rare‐earth sublattices and describing complex ionic‐covalent bonding. The hybrid functional WC1LYP, based on the generalized gradient approximation, showed itself well in calculating the Raman spectrum of aluminosilicates and pyrosilicates . With a 16% of nonlocal Hartree–Fock, the density functional theory exchange part is described by the Wu–Cohen model, one feature of which is that it does not use adjustable parameters.…”

First‐Principles Study of Elastic Properties of Rare‐Earth Oxyorthosilicates R2SiO5

“…For A-type oxyorthosilicates, the changes remain within one hundredth of the angstrom and within one thousandth of the angstrom for the B-type. [13] Therefore, the rare-earth sublattice has a weak effect on silicon-oxygen complexes in the structure of these silicates, and there is strong covalent bonding between the Si and O ions.…”

“…The calculated Si—O bond lengths for Lu 2 SiO 5 are nearly equal to those in SiO 4 tetrahedra in Lu 2 Si 2 O 7 . [ 13 ] Therefore, the rare‐earth sublattice has a weak effect on silicon–oxygen complexes in the structure of these silicates, and there is strong covalent bonding between the Si and O ions.…”

“…[11] The functional has been successfully used to describe the properties of aluminosilicates and pyrosilicates. [12,13] In this functional, the DFT part of the exchange interaction was calculated using the WC (Wu-Cohen) model and general gradient approximation (GGA). [14] A distinguishing feature of this method is that it was developed without the use of the fitting parameters.…”