Thermodynamic geometry of a kagome Ising model in a magnetic field

► The scalar curvature is calculated exactly for 2d Ising model in a magnetic field. ► The Fisher formula can be obtained just by using a geometric representation. ► The scalar curvature has a singularity which is exactly corresponds to the critical point. ► The scalar curvature behaves as tα−1 which is different from naive expectation. ► This study shed some light on unknown scaling behavior of thermodynamic geometry for α⩽0.