A Hirshfeld-I interpretation of the local moment composition of the quadrupole moments of the halogenated acetylenes FCCF, ClCCCl, BrCCBr, and ICCI

► Electron density expressed as a sum of atomic densities using Hirshfeld-I technique. ► Molecular quadrupole moment Θmol written as sum of local atomic moments. ► Atomic charges obtained by fitting Θmol not consistent with Hirshfeld-I charges. ► Small Θmol of FCCF due to cancelation of charge, atomic dipole contributions. ► Atomic charge, dipole, quadrupole contributions to Θmol positive for all but FCCF.