Hydrogen bonding characterization in water and small molecules.

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Quantum Chemistry

Background:

• Hydrogen bonds are crucial in chemistry and biology.
• Understanding hydrogen bond characteristics is essential for molecular interactions.

Purpose of the Study:

• To theoretically investigate hydrogen bonds across various systems and bond strengths.
• To characterize hydrogen bonds using electronic and structural properties.
• To develop a geometric parameter for estimating covalent contributions to hydrogen bonds.

Main Methods:

• First-principles calculations based on density functional theory (DFT).
• Utilized generalized gradient approximation, hybrid, and van der Waals corrected functionals.
• Computed structural, energetic, and electrostatic properties, including induced dipole moments.

Main Results:

• Characterized hydrogen bonds using differential electron density and maximally localized Wannier functions.
• Developed a geometric bonding parameter correlated with the Mayer bond order parameter.
• Quantified cooperative and anticooperative effects in water clusters and ice.

Conclusions:

• The study provides insights into the nature of hydrogen bonds, from weak to strong.
• A novel geometric parameter offers an estimate of the covalent character of hydrogen bonds.
• Cooperative effects significantly influence hydrogen bond formation in condensed phases.