采用“断键模型”计算了立方晶体理想表面的悬键密度,进而计算了其表面自由能(SFE).结果表明:对于理想(1×1)-(hkl)表面,SFE可以表示为键能、键长和表面方向的函数.该模型简单地解决了晶体SFE各向异性的理论问题.根据该模型和Wulff定则得出的晶体平衡形状与理论完全一致;同时,计算结果也表明面心立方和体心立方晶体的平衡形状与其三维第一布里渊区重合. The surface area free energy (SFE) of the cubic crystal was calculated by using the “broken bond model”. The results show that the SFE can be expressed as the bond energy for the ideal (1 × 1) - (hkl) , Bond length and surface orientation.The model simply solves the theoretical problem of the anisotropy of the crystal SFE.According to the model and the Wulff’s theorem, the shape of the crystal equilibrium is completely consistent with the theory. Meanwhile, the calculation results also show that the facet The equilibrium shape of the cubic and body-centered cubic crystals coincides with its three-dimensional first Brillouin zone.