Hydrostatic pressure dependence of the superconducting transition temperature in Hg-based cuprates within the Harshman–Fiory model

• HF model describes the pressure dependence of T c in Hg cuprates. • d T c /dP stays nearly constant across optimal doped Hg-12(n − 1)n series. • Charge transfer offsets lattice-compression effects under pressure. The hydrostatic-pressure dependence of the superconducting transition temperature T c in Hg-based cuprates is examined on the basis of the Harshman–Fiory interlayer Coulomb-coupling model, with explicit consideration of lattice compressibility and pressure-induced charge redistribution. Across the optimally doped Hg-12(n − 1)n series, the calculated values of d T c / d P remain confined to a narrow interval despite the increasing number of C u O 2 layers. This weak variation is attributed to a compensation between structural and electronic contributions under pressure. The calculated results are consistent with available experimental trends and suggest that charge redistribution plays an important role in the pressure response of Hg-based cuprates within the considered pressure range.