Naveena Kumara, A.N.Ahmed Rizwan, C.L.A.Hegde, K.Ali, M.S.Ajith, K.M.2026-02-042023General Relativity and Gravitation, 2023, 55, 1, pp. -17701https://doi.org/10.1007/s10714-022-03050-yhttps://idr.nitk.ac.in/handle/123456789/22189In this article, we analytically investigate the microstructure of a five-dimensional neutral Gauss–Bonnet black hole, in the background of anti-de Sitter spacetime, by using the scalar curvature of the Ruppeiner geometry constructed via adiabatic compressibility. The microstructure details associated with the small-large black hole phase transition are probed in the parameter space of pressure and volume. The curvature scalar shows similar properties for both phases of the black hole, it diverges at the critical point with a critical exponent 2, and approaches zero for extremal black holes. We show that the dominant interaction among black hole molecules is attractive. This study also confirms that the nature of the microstructure interaction remains unchanged during the small-large black hole phase transition, even though the microstructures are different for both phases. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.Black hole microstructureBlack hole thermodynamicsExtended phase spaceFive-dimensional neutral Gauss–Bonnet black holeRuppeiner geometryvan der Waals fluid