It is shown by considering 76 halogen- and hydrogen-bonded complexes B⋯XY and B⋯HX (where B is a Lewis base N₂, CO, C₂H₂, C₂H₄, H₂S, HCN, H₂O, PH₃ or NH₃ and X, Y are F, Cl, Br or I) that the intermolecular stretching force constants k_σ (determined from experimental centrifugal distortion constants via a simple model) and the intermolecular dissociation energies D_σ (calculated at the CCSD(T)(F12*)/cc-pVDZ-F12 level of theory) are related by D_σ = C_σk_σ, where C_σ = 1.50(3) × 10³ m² mol⁻¹. This suggests that one-dimensional functions implying direct proportionality of D_σ and k_σ, (e.g. a Morse or Rydberg function) might serve as reduced radial potential energy functions for such complexes.