Open AccessCorrelation between structure characteristics and pair radial distribution function in Silica glass under compression
Author(s) -
Lan Mai Thi
Publication year - 2018
Publication title -
tạp chí khoa học đại học quốc gia hà nội: toán - lý (vnu journal of science: mathematics - physics)
Language(s) - English
Resource type - Journals
eISSN - 2615-9341
pISSN - 2588-1124
DOI - 10.25073/2588-1124/vnumap.4304
Subject(s) - radial distribution function , tetrahedron , materials science , octahedron , crystallography , molecular dynamics , pair distribution function , coordination number , oxygen atom , phase (matter) , ion , chemical physics , chemistry , crystal structure , molecule , computational chemistry , physics , organic chemistry , quantum mechanics
We have studied structure of silica glass at different pressures and temperature of 300K by using Molecular Dynamics simulation (MD) method. The model consists of 6000 atoms (2000 Si, 4000 O atoms) with the periodic boundary condition. We applied the Morse-Stretch potentials which describe the pairwise interactions between ions for SiO2 system. There is structural phase transformation from tetrahedra (SiO4) to octahedra (SiO6) network structure. There is splitting in the Si-Si pair radial distribution function (PRDF) at high pressure (100 GPa). The original of this splitting relates to the edge- and face-sharing bonds. The new second peak of the O-O PRDF at the high pressure originates from oxygen atoms of the edge-sharing bonds. Thus, there is rearrangement of O atoms. O atoms have tendency to more order arrangement that leads to form some oxygen hcp and fcc structure in the model at high pressure.