Computer simulation of GeO2 liquid

Local structure of liquids Al2O3 and GeO2 under densification

“…For this we use the Verlet algorithm with a time step of 0.4 fs. The system is generated, starting from liquid model obtained from previous study [20]. With this liquid we prepare 9 systems at temperature of 3000 K and pressure ranging from 0 to 50 GPa.…”

“…The technical detail about the simulation can be found in Ref. [20,21]. Finally, 9 systems of 2000 atoms (800 Al and 1200 O) with Born-Mayer potentials [19] and at temperature of 3000 K are constructed using the same calculation schedule.…”

“…Those studies predict the transition from tetrahedral at low-density state to octahedral network structure at high-density state. Furthermore, substantial structural change is observed not only in density and coordination number, but also in void and void aggregation [20,21]. However, the local structure of these liquids is so far understood and the present simulation is devoted to shed new light on this problem.…”

“…For example, in situ X-ray absorption measurement shows that fourcoordinated germanium is dominant in liquid germanate with increasing pressure up to 2.3 GPa and then this liquid shows an abruptly fourfold-to-sixfold coordination change around 3 GPa [2]. Computer simulation often is employed to examine the structural change at atomic level [13][14][15][16][17][18][19][20][21][22][23]. In principle, ab-initio scheme is able to reproduce many physical properties of real systems [24,25], but this approach is limited to several hundred atoms at most.…”

“…Hence the classical molecular dynamic (MD) simulation is an effective way to deal with the problem where the short-and intermediate-range order is involved. Pressure-induced structural transformation has been simulated for liquid germania [14,17,20] and alumina [16,21]. Those studies predict the transition from tetrahedral at low-density state to octahedral network structure at high-density state.…”