Recently synthesized Kagome compounds AV3Sb5 attract great attention due to the unusual coexistence of the topology, charge density wave, and superconductivity. In this work, based on the band structures for CsV3Sb5 in the pristine phase, we construct an effective six-band model for the low-energy processes; utilizing the random phase approximation on the effective six-band model, we show that the E1u ( p wave ) pairing dominates in the region of 0 < U < 0.32 eV, the A2g ( I wave ) in the region of 0.32 < U < 0.75 eV and the E2g ( d wave ) in the region of 0.75 < U < 1 eV. Considering that the correlation in AV3Sb5 is weak or intermediate, these results suggest that pairing symmetry is A2g ( I-wave ) in the CsV3Sb5, which can explain some recent experiments about pairing symmetry.

Recently synthesized Kagome compounds AV 3 Sb 5 attract great attention due to the unusual coexistence of the topology, charge density wave and superconductivity. In this Letter, based on the band structures for CsV 3 Sb 5 in pristine phase, we fit an effective 6-band model for the low-energy processes; utilizing the random phase approximation (RPA) on the effective minimal model, we obtain the momentum-resolved dynamical spin susceptibility; attributing the spin-fluctuation pairing mechanism, we find that the superconducting pairing strengths increase with the lift of the Coulomb correlation, and the superconductive pairing symmetry is singlet, most probably with the d xy symmetry in the intermediate to strong Coulomb correlated regime, indicating the unconventional superconductivity in Kagome compounds AV 3 Sb 5 .

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