New Multicomponent Optimization Scheme for Equiatomic Vanadium-Titanium Nanoparticle Study.

We present a new multicomponent structure prediction method named MRS-Swap searching, which is inspired by space symmetry and swap of different atomic species. For the pure titanium cluster, a new ground-state structure of the Ti 20 cluster with higher symmetry relative to a previous study was found by our method. Based on the structural analysis of Ti n (n = 2k, k = 2-11), V n (n = 2k, k = 2-11), and Ti n V m ( n = m = 2-11) systems, we found that the lowest energy structures of these three systems are very similar, which indicates that equiatomic vanadium-titanium-mixed clusters do not change their ground-state structure relative to the same size pure vanadium and titanium cluster. According to the structure-activity relationship, we conclude that the yield strength (σ) of macro vanadium-titanium alloy is between pure titanium and pure vanadium metal, and this can be expressed through σ(Ti) > σ(TiV) > σ(V). The X-ray diffraction results show that the V 2 Nb, TiVNb, and Ti 2 Nb alloys also have the same BCC structure, which may be related to their microstructure. Our method and results can be helpful for future multicomponent alloy design.