Quantum mechanical force field for hydrogen fluoride with explicit electronic polarization.

Area of Science:

• Computational Chemistry
• Quantum Mechanics
• Materials Science

Background:

• Explicit polarization (X-Pol) theory models electronic polarization and intermolecular interactions.
• Developing accurate quantum mechanical force fields is crucial for simulating chemical systems.
• Previous work established the XP3P model for liquid water using X-Pol theory.

Purpose of the Study:

• To extend X-Pol theory and develop a quantum mechanical force field for liquid hydrogen fluoride (HF).
• To parameterize and validate the XPHF model for both gas-phase HF clusters and liquid HF.
• To assess the accuracy of the XPHF model against experimental data and ab initio calculations.

Main Methods:

• Developed the XPHF model based on the polarized molecular orbital (PMO) semiempirical method.
• Introduced a fluorine parameter set for PMO within the dipole-preserving polarization consistent point charge model.
• Validated the model using gas-phase HF clusters and simulations of liquid HF at various state points.

Main Results:

• The XPHF model demonstrated good agreement with experimental and ab initio results for gas-phase HF clusters.
• The model accurately reproduced structural properties like radial distribution functions for liquid HF.
• Thermodynamic properties including diffusion coefficients and densities were reasonably predicted for liquid HF.

Conclusions:

• The XPHF model provides a robust quantum mechanical force field for simulating hydrogen fluoride.
• This work successfully extends X-Pol theory to a new chemical system, demonstrating its versatility.
• The validated XPHF model serves as a valuable tool for future research on hydrogen fluoride systems.