Toward a realistic density functional theory potential energy surface for the H5+ cluster

Area of Science:

• Computational chemistry
• Quantum chemistry
• Physical chemistry

Background:

• Protonated hydrogen clusters are fundamental in understanding chemical reactions and material properties.
• Accurate characterization of their potential energy surfaces is crucial for predicting their behavior.

Purpose of the Study:

• To characterize the potential energy surface of the H(5)(+) cluster using density functional theory (DFT).
• To evaluate the accuracy of DFT, specifically the B3(H) functional, against high-level ab initio methods.
• To investigate the topological features and intermolecular interactions of the H(5)(+) system.

Main Methods:

• Density functional theory (DFT) calculations with various functionals.
• Comparison with ab initio coupled-cluster single double with perturbative triples (CCSD(T)) calculations.
• Identification of stationary points (minima and saddle points) and analysis of intermolecular interactions.

Main Results:

• DFT calculations using the B3(H) functional accurately reproduce the H(5)(+) potential energy surface.
• The B3(H) functional correctly describes the energy difference between key configurations and asymptotic interaction behavior.
• Calculated binding energies and dissociation enthalpies align well with benchmark ab initio and experimental data.

Conclusions:

• DFT with the B3(H) functional is a reliable method for studying H(5)(+) potential energy surfaces.
• This approach can be effectively used for first-principles molecular dynamics simulations of protonated hydrogen clusters.
• The findings provide a foundation for understanding the dynamics and properties of these important chemical species.