Fig. 2: Nb3Cl8 as a cluster Mott insulator.
From: Correlated flat bands and quantum spin liquid state in a cluster Mott insulator
a Electronic structure from a density functional theory + dynamical mean-field theory (DFT + DMFT) calculation with Hubbard interaction strength U = 4.0 eV, and Hund coupling strength J = 0.8 eV. b Renormalization of the flat bands from a DFT + molecular-orbital DMFT (MO-DMFT) calculation with U = 0.75, V = 0.6 eV. The position of the chemical potential (EF) is arbitrary inside the Mott gap and has been shifted to the bottom of the upper Hubbard band in this plot.
