Hydrogen-bonding networks from first-principles: exploring the guanidine crystal

Area of Science:

• Solid-state chemistry
• Computational materials science
• Molecular crystallography

Background:

• Hydrogen bonding significantly influences molecular crystal structures, leading to complex arrangements.
• Understanding these interactions is crucial for predicting and designing crystalline materials.
• Guanidine serves as a model system due to its chemical importance and intricate crystal structure.

Purpose of the Study:

• To develop and apply a computational approach for analyzing hydrogen-bonded networks in molecular crystals.
• To investigate the three-dimensional hydrogen-bonded structure of guanidine.
• To quantify the cooperative interactions contributing to guanidine's crystalline stability.

Main Methods:

• Plane-wave density-functional theory (DFT) calculations.
• Supercell techniques for modeling crystalline and fragmented structures.
• Analysis of hydrogen-bonded networks in 3D, 2D, 1D, and 0D forms.

Main Results:

• The computational approach successfully quantifies hydrogen-bonded networks.
• Analysis provides insights into the initially proposed layered structure of guanidine.
• Both stabilizing and destabilizing cooperative interactions within the crystal were identified.

Conclusions:

• The study validates a computational methodology for studying hydrogen bonding in molecular crystals.
• The findings offer a detailed understanding of guanidine's crystal structure and the role of cooperative interactions.
• This approach can be extended to other molecular crystals for structure-property relationship studies.