Ion molecules with general chemical formula as [Li(H2O)] (n=1,2,3), have been chosen as model species toinvestigate the chemical properties of hydrated lithium cations. The RHF(SCVS)/UGBS level of calculationhas been used for obtaining equilibrium geometries and Rho(r) functions (electron density distributions). By theaid of fundamental physical theorems implemented in Quantum Theory of Atoms in Molecules (QTAIM), thestructures, the physical nature of chemical bonds and all atomic properties have been determined for citedspecies at the mentioned theoretical level. Then these atomic properties have been compared with theircorresponding values in isolated Li+ and H20 ingredients. Fragments of a molecule, Interaction andCoordination are the three fundamental concepts in this field, which have been fully discussed and redefinedunequivocally in a new context. Manuscript profile