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 cluster with higher symmetry relative to a previous study was found by our method. Based on the structural analysis of Ti (n = 2k, k = 2-11), V (n = 2k, k = 2-11), and TiV ( = = 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 VNb, TiVNb, and TiNb 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.