Ab initio model study on a water molecule between graphite layers

Interactions between a water molecule and one- and two-layer graphite were calculated by ab initio Hartree-Fock (HF) method. Eclipsed coronene dimer (C₂₄H₁₂)₂ was used as the two-layer graphite model, to study the behavior of a water molecule in the pressure between two graphite layers. Three one-layer models, C₁₆H₁₀, C₄₂H₁₆, and C₈₀H₂₂, were used as reference to investigate the influence of the adsorption site, the orientation of the water molecule, and the size of the model. Only minor differences were found in the three adsorption sites. The HF interaction was weaker with larger models and stronger with larger basis set (6-31G*).