Abstract: Electronic band structure is a key property in solid materials. It is the connecting lines of energy eigenvalues of the high symmetric points in the Brillouin zone. As the twodimensional layered structure is rolled into a tubular structure, the corresponding reciprocal space will also transform from two dimension to one dimension. Therefore, the energy band of a onedimensional structure can be obtained by folding the corresponding twodimensional Brillouin zone. In this paper, the Brillouin zone folding method of band structure is discussed from two examples, graphene and singlewalled carbon nanotubes, as well as the twodimensional La3Ni2O7 layered structure and its corresponding nanotubes by rolling the La3Ni2O7 layer.

Key words: band structure, Brillouin zone, Brillouin zone folding methods, firstprinciples, tightbinding