Electron correlations in the kagome metals AV 3 Sb 5   ( A = K ,   Rb ,   Cs )

The investigation of electronic order-quantum phase interplay in kagome lattices commonly employs the extended kagome-Hubbard model, where the critical parameters comprise on-site $(U)$ and intersite $(V)$ Coulomb interactions. In prototypical kagome metals AV₃Sb₅ (A=K, Rb, Cs), the geometrically frustrated quasi-two-dimensional architecture induces pressure-dependent complexity in vanadium d-electron correlations, necessitating systematic theoretical scrutiny. Utilizing the d-dp model within constrained random phase approximation (cRPA), we quantified U, V, and Hund's coupling J under hydrostatic pressure (0--9 GPa). While KV₃Sb₅ and RbV₃Sb₅ exhibit pressure-insensitive interaction parameters, CsV₃Sb₅ manifests anomalous discontinuities in U and V near 0.2 GPa, suggesting a first-order electronic phase transition. This work establishes cRPA-derived interaction landscapes as critical predictors for pressure-tunable quantum phenomena in correlated kagome systems, offering insight into the understanding of the interplay between the charge density wave transition and the double superconductivity dome in CsV₃Sb₅ at low pressure.