Periodic Hirshfeld Atom Refinement

Area of Science:

• Crystallography
• Quantum Chemistry
• Materials Science

Background:

• Hirshfeld Atom Refinement (HAR) accurately refines hydrogen atom parameters from X-ray diffraction data.
• Conventional HAR is limited to molecular crystals, excluding periodic network structures.

Purpose of the Study:

• Introduce a new variant of periodic HAR (pHAR) applicable to any periodic-network structure.
• Ensure compatibility with conventional HAR using atom-centered Gaussian orbitals and Bloch wave formalism.

Main Methods:

• Developed a new variant of periodic HAR (pHAR).
• Employed atom-centered Gaussian orbitals with a Bloch wave formalism.
• Tested pHAR against single-crystal diffraction data for boranes and borates.

Main Results:

• pHAR shows close agreement of X-H bond lengths with neutron diffraction data.
• Achieved improved precision in structural parameters for periodic networks.
• Nearly doubled the available reliable experimental data on B-H bonds.

Conclusions:

• pHAR successfully extends HAR to periodic-network structures.
• The method provides highly precise X-H bond lengths, particularly for B-H bonds.
• pHAR significantly enhances the structural analysis capabilities in crystallography.