Open AccessФотонный спектр Eu-=SUB=-2-=/SUB=-Sn-=SUB=-2-=/SUB=-O-=SUB=-7-=/SUB=-: ab initio расчет
Author(s) -
В.А. Чернышев,
П.А. Агзамова,
А.В. Архипов
Publication year - 2020
Publication title -
žurnal tehničeskoj fiziki
Language(s) - English
Resource type - Journals
eISSN - 1726-748X
pISSN - 0044-4642
DOI - 10.21883/os.2020.11.50170.124-20
Subject(s) - linear combination of atomic orbitals , ab initio , formalism (music) , phonon , raman spectroscopy , crystal (programming language) , atomic physics , ab initio quantum chemistry methods , density functional theory , hybrid functional , normal mode , chemistry , molecular physics , physics , materials science , vibration , computational chemistry , condensed matter physics , quantum mechanics , molecule , art , musical , basis set , computer science , visual arts , programming language
Crystal structure and phonon spectrum of crystal Eu2Sn2O7 were studied within the framework of density functional theory and MO LCAO approach. The calculations were performed by using hybrid functional that takes into account both local and nonlocal (in the Hartree–Fock formalism) exchange. The calculations were performed in the CRYSTAL17 program intended for simulating periodic structures in the MO LCAO approximation.The fundamental vibration frequencies of Eu2Sn2O7 were calculated. The frequencies, intensities and types of the Raman and the IR-active modes have been calculated. An analysis of the displacement vectors obtained from the ab initio calculation, made it possible to estimate the degree of the ion participation in the vibrational mode. The elastic constants of the crystal have been calculated too.