Predicted atomic arrangement of Mg67Zn28Ca5 and Ca50Zn30Mg20 bulk metallic glasses by atomic simulation

• Techniques of obtaining reliable potential parameters and amorphous models
• Differences of local structures between Mg67Zn28Ca5 and Ca50Zn30Mg20 bulk metallic glass
• The chemical affinities of Mg67Zn28Ca5 and Ca50Zn30Mg20 bulk metallic glass

The microstructures of Mg-based Mg67Zn28Ca5 and Ca-based Ca50Zn30Mg20 bulk metallic glasses are predicted by the simulated-annealing basin-hopping method with the tight-binding potential function. The parameters of Mg, Zn, and Ca, and the cross-element pairs of the TB potential are first fitted by the force-matching method with the reference data from experimental results and the density functional theory calculation. The structures from the SABH methods reveal that the average bond lengths of different atomic pairs are almost the same for these two BMGs. However, the microstructures found by the Honeycutt–Anderson pair analysis are very different. For Mg67Zn28Ca5, the perfect icosahedral local structure occupies the highest fraction, while for Ca50Zn30Mg20 the distorted icosahedral local structures are predominant.