The study investigates the electronic structure of La3Ni2O7 in its alternating monolayer-trilayer (1313) phase, which exhibits superconductivity near 80 K under high pressure. Using angle-resolved photoemission spectroscopy (ARPES), the researchers measure the electronic structure of 1313 samples and find significant differences compared to the previously studied bilayer (2222) structure. The 1313 structure hosts a flat band with a different binding energy, an additional electron pocket, and band splittings. Local-density approximation (LDA) calculations reveal strong renormalizations of the Ni-d2 and Ni-d2+u2 derived bands, suggesting strong correlation effects. These findings highlight important differences in the electronic structure due to distinct structural motifs with the same stoichiometry, which may be relevant to the high-temperature superconductivity observed in La3Ni2O7. The study also discusses the potential role of the 1313 structure in hosting superconductivity and the possibility of interface-induced superconductivity between different structural phases.The study investigates the electronic structure of La3Ni2O7 in its alternating monolayer-trilayer (1313) phase, which exhibits superconductivity near 80 K under high pressure. Using angle-resolved photoemission spectroscopy (ARPES), the researchers measure the electronic structure of 1313 samples and find significant differences compared to the previously studied bilayer (2222) structure. The 1313 structure hosts a flat band with a different binding energy, an additional electron pocket, and band splittings. Local-density approximation (LDA) calculations reveal strong renormalizations of the Ni-d2 and Ni-d2+u2 derived bands, suggesting strong correlation effects. These findings highlight important differences in the electronic structure due to distinct structural motifs with the same stoichiometry, which may be relevant to the high-temperature superconductivity observed in La3Ni2O7. The study also discusses the potential role of the 1313 structure in hosting superconductivity and the possibility of interface-induced superconductivity between different structural phases.