Thanks to the recent progress in high-performance computational environments, the range of applications of computational metallurgy is expanding very rapidly [1].We have performed large-scale molecular dynamics simulations up to 10 million atoms for understanding the solidification of metals and related properties [1-4].In particular, million-atom molecular dynamics simulations captured the spontaneous evolution of anisotropy in a solid nucleus in an undercooled melt and homogeneous nucleation without any inducing factor, which is followed by grain growth [1,4].Here, our recent progress in this issues will be discussed.