Molecular dynamics simulations combining potentials mapping technique have been performed to investigate the structure of: binary liquid Li-Mg alloys at a constant temperature (924 K). Pair correlation function, bond ...Molecular dynamics simulations combining potentials mapping technique have been performed to investigate the structure of: binary liquid Li-Mg alloys at a constant temperature (924 K). Pair correlation function, bond orientational order and pair analysis approach are adopted to give geometrical descriptions on atom arrangement. The trends of splitting of second-peak in pair correlation function, the orientational order parameters and evolution of various symmetries of bonded pairs, etc., vs composition have been examined. The difference and concordance between the bond-orientational order and pair analysis have been first given out. Based on the distribution of attractive part of potentials, it is concluded that the attractive part would dominate the characterization of structure in liquid metals. In addition, icosahedra, defective icosahedra, Frank-Kasper polyhedra and Bernal hole polyhedra formed in liquid Li-Mg alloys are also counted.展开更多
The similarity and difference between the bond orientational order and pair analysis methods have been first identified with the help of molecular dynamics simulation and the steepest descent minimization of potential...The similarity and difference between the bond orientational order and pair analysis methods have been first identified with the help of molecular dynamics simulation and the steepest descent minimization of potentials techniques. The binary liquid K-Rb alloys are chosen as an example. Results show that the bond orientational order parameters may be a relevant direct measurement on the perfection of an icosahedron. The PA formula (1551 bonded pairs) is, however, responsible for the total number of various icosahedra. In addition, it is found that pair analysis approach is more sensible to local structure than that for bond orientational order.展开更多
文摘Molecular dynamics simulations combining potentials mapping technique have been performed to investigate the structure of: binary liquid Li-Mg alloys at a constant temperature (924 K). Pair correlation function, bond orientational order and pair analysis approach are adopted to give geometrical descriptions on atom arrangement. The trends of splitting of second-peak in pair correlation function, the orientational order parameters and evolution of various symmetries of bonded pairs, etc., vs composition have been examined. The difference and concordance between the bond-orientational order and pair analysis have been first given out. Based on the distribution of attractive part of potentials, it is concluded that the attractive part would dominate the characterization of structure in liquid metals. In addition, icosahedra, defective icosahedra, Frank-Kasper polyhedra and Bernal hole polyhedra formed in liquid Li-Mg alloys are also counted.
文摘The similarity and difference between the bond orientational order and pair analysis methods have been first identified with the help of molecular dynamics simulation and the steepest descent minimization of potentials techniques. The binary liquid K-Rb alloys are chosen as an example. Results show that the bond orientational order parameters may be a relevant direct measurement on the perfection of an icosahedron. The PA formula (1551 bonded pairs) is, however, responsible for the total number of various icosahedra. In addition, it is found that pair analysis approach is more sensible to local structure than that for bond orientational order.
