A systematic study of aqueous microsolvation of CdCl₂ was conducted using density functional theory (DFT) and Born-Oppenheimer molecular dynamics (BO-MD). The structures and binding energies of CdCl₂-(H₂O)ₙ clusters (n = 1–24) were calculated at the B3PW91/6-31G** level. The solvation patterns were verified at the MP2/AVTZ level for n < 6. Unlike HgCl₂, Cd forms four equatorial orbital interactions with water for n > 6, leading to a planar square bipyramid hexacoordination around Cd. The first solvation shell is fully attained with 12 water molecules. The water binding energies for CdCl₂ are much larger than those for HgCl₂ due to stronger Cd-Ow interactions. For the largest system, CdCl₂-(H₂O)₂₄, both penta- and hexacoordinated structures are found. BO-MD simulations at 700 K reveal that the pentacoordinated Cd species is more stable. The Cd-Ow radial distribution function shows a bimodal distribution with two maxima at 2.4 Å and 4.2 Å, indicating different coordination spheres. The Gibbs free energy of the hexacoordinated Cd structure is 5.6 kcal/mol lower than that of the pentacoordinated structure. The study highlights the importance of water binding energies and coordination patterns in understanding the solvation behavior of CdCl₂ in aqueous environments. The results provide insights into the structural and energetic properties of CdCl₂ in solution, which are crucial for understanding its environmental and biological impacts.A systematic study of aqueous microsolvation of CdCl₂ was conducted using density functional theory (DFT) and Born-Oppenheimer molecular dynamics (BO-MD). The structures and binding energies of CdCl₂-(H₂O)ₙ clusters (n = 1–24) were calculated at the B3PW91/6-31G** level. The solvation patterns were verified at the MP2/AVTZ level for n < 6. Unlike HgCl₂, Cd forms four equatorial orbital interactions with water for n > 6, leading to a planar square bipyramid hexacoordination around Cd. The first solvation shell is fully attained with 12 water molecules. The water binding energies for CdCl₂ are much larger than those for HgCl₂ due to stronger Cd-Ow interactions. For the largest system, CdCl₂-(H₂O)₂₄, both penta- and hexacoordinated structures are found. BO-MD simulations at 700 K reveal that the pentacoordinated Cd species is more stable. The Cd-Ow radial distribution function shows a bimodal distribution with two maxima at 2.4 Å and 4.2 Å, indicating different coordination spheres. The Gibbs free energy of the hexacoordinated Cd structure is 5.6 kcal/mol lower than that of the pentacoordinated structure. The study highlights the importance of water binding energies and coordination patterns in understanding the solvation behavior of CdCl₂ in aqueous environments. The results provide insights into the structural and energetic properties of CdCl₂ in solution, which are crucial for understanding its environmental and biological impacts.