In the present study, the cooperative and diminutive interplay between halogen, hydride, and cation-σ interactions are studied in HMgH···Li+(Na+)···NCCl, Li+(Na+)···HMgH···ClCN and HMgH···ClCN···Li+(Na+) complexes by means of ab initio calculations. To better understand the cooperative or diminutive effects in the ternary systems, the corresponding binary complexes are also considered. The estimated cooperative energies (Ecoop) are all negative for the systems with CNCl in the central location, while positive in the other systems. In addition, complexes involving cation-σ interactions have the largest stability energy among studied complexes. The electronic properties of the complexes are analyzed using parameters derived from the quantum theory of atoms in molecules methodology.