Quantum chemical calculations are performed to gauge the effect of cation-pi and hydrogen bonding interactions on each other. M-phenol-acceptor (M = Li+ and Mg2+; acceptor = H2O, HCOOH, HCN, CH3OH, HCONH2 and NH3) is taken as a model ternary system that exhibits the cation-pi and hydrogen bonding interactions. Cooperativity is quantified and the computed positive cooperativity between cation-pi and hydrogen bonding interactions is rationalized through reduced variational space (RVS) and charge analyses.