Potential energy surfaces of antiparallel water-water interactions

• Published in: Journal of molecular liquids 2023-11, Vol.389, p.122758, Article 122758
• Main Authors: Milovanović, Milan R., Živković, Jelena M., Ninković, Dragan B., Zarić, Snežana D.
• Format: Article
• Language: English
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2023.122758

•Potential energy surface of antiparallel water-water interaction was calculated.•20,010 geometries were calculated at high quantum chemical level, CCSD(T)/CBS.•The interaction energy of the most stable antiparallel water-water interaction is −4.22 kcal/mol.•The antiparallel water-water interaction is stronger than weak hydrogen bonds.•Antiparallel water-water interaction is a significant interaction between two water molecules in liquid water. Antiparallel water-water interaction is a significant interaction between two water molecules and plays an important role in liquid water. The potential energy surface of antiparallel water-water interaction was calculated at accurate CCSD(T)/CBS level of theory by systematic changes of the torsion angle THOHO, parallel displacement r, normal distance R, and water-water dihedral angle Pa/Pb. The results show that the most stable geometry of antiparallel water-water interaction has an interaction energy of −4.22 kcal/mol and THOHO = 140°. A significant portion of the antiparallel interactions have interaction energies more negative than −2.0 kcal/mol. The angle α of the most stable geometries of antiparallel water-water interactions is in the range 110°–120°. Comparison with classical hydrogen bonds in water dimers shows that hydrogen bonds with values of angle α