Ab initio molecular dynamics study of collective dynamics in liquid Tl: Thermo-viscoelastic analysis

被引:0
作者
Bryk, Taras [1 ,2 ]
Demchuk, Taras [1 ]
机构
[1] NAS Ukraine, Inst Condensed Matter Phys, Svientsitskii St 1, UA-79011 Lvov, Ukraine
[2] Lviv Polytech Natl Univ, Inst Appl Math & Fundamental Sci, S Bandera Str 12, UA-79013 Lvov, Ukraine
来源
16TH INTERNATIONAL CONFERENCE ON LIQUID AND AMORPHOUS METALS (LAM-16) | 2017年 / 151卷
关键词
TOTAL-ENERGY CALCULATIONS; MODES; METALS;
D O I
10.1051/epjconf/201715102001
中图分类号
O469 [凝聚态物理学];
学科分类号
070205 ;
摘要
We studied collective dynamics of pure liquid metal Tl using a combination of ab initio molecular dynamics (AIMD) simulations and a thermo-viscoelastic model applied to calculations of dynamic eigenmodes and dispersion of collective excitations in particular. We found that for liquid Tl at ambient pressure the transverse current spectral functions obtained directly in ab initio simulations for wave numbers larger than first pseudo-Brillouin-zone boundary contain two low-and high-frequency peaks that is an evidence of emergence of the unusually high-frequency transverse modes as it was observed before in liquid Li at very high pressures. The thermo-viscoelastic dynamic model shows perfect reproduction of the simulation-derived longitudinal current auto-correlation functions, and the acoustic eigenmodes are in nice agreement with the peaks of the longitudinal current spectral functions up to the first pseudo-Brillouin-zone boundary. The deviation of the dynamic eigenmodes from peak positions at higher wave numbers gives evidence of L-T coupling effects.
引用
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页数:9
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