Molecular dynamics studies the effect of structure MgSiO_3 bulk on formation process geology of the Earth

摘要

The paper studies the effect of temperature (T), (T = 300, 3200, 4000, 5000, 6000, 7000 K) at pressure P = 0 GPa; pressure (P), (P = 0, 100, 200, 300, 350, 400 GPa) at T = 7000 K and thermal annealing time (t), t = 47.8 ps (after 10~5 steps) at T = 7000 K, P = 400 Gpa) on the structure of MgSiO_3 bulk 3000 atoms by Molecular Dynamics (MD) simulation using Born-Mayer (BM) pair interaction potential and periodic boundary conditions. The structural results are analyzed through the Radial Distribution Function (RDF), the Coordination Number (CN), the angle distribution, size (l), total energy of the system (E_(tot)) and the bonding lengths. The results show that the temperature and pressure had influenced the structural properties of MgSiO_3 bulk and formation process geology of the Earth. In addition, the center of the Earth with X = 7000 K and P = 350 GPa has appearance and disappearance of the Si-Si, Si-O, O-O, Si-Mg, O-Mg, Mg-Mg bonds and SiO_4, SiO_5, SiO_6, MgO_3, MgO_4, MgO_5, MgO_6, MgO_7, MgO_8, MgO_9, MgO_(10), MgO_(11), MgO_(12) angle distributions. When increasing the depth of the Earth's surface (h) lead to size (l) of MgSiO_3 decreases, total energy of the system (E_(tot)) increases, position of first peak of Radial Distribution Function (RDF) is (r), height of RDF is g(r) varies greatly with h from h = 0 km to h = 1820 km, gradually decreasing with h from h = 2000 km to h = 3200 km and the smallest structural change with h > 3200 km that shows has influence affects on the geological formation of the Earth.