A new molecular-dynamics based approach for molecular crystal structure search

Area of Science:

• Materials Science
• Computational Chemistry
• Crystallography

Background:

• Determining crystal structures of molecular solids can be challenging, especially with low-quality or complex diffraction data.
• Traditional methods may struggle to identify the most stable polymorphs automatically.

Purpose of the Study:

• To introduce a new computational method for discovering candidate crystal structures of molecular solids.
• To automate the selection of the most stable crystal structures.
• To facilitate crystal structure solution from difficult diffraction datasets.

Main Methods:

• Utilizing molecular-dynamics simulations of an artificial periodic system with a small unit cell.
• Observing spontaneous transitions between ordered and disordered states within the simulations.
• Employing the observed transitions to automatically select the most stable structures.

Main Results:

• The proposed molecular-dynamics approach successfully identifies candidate crystal structures.
• The method demonstrated its capability in selecting the most stable structures.
• Successful application of the method was shown for H2O-ice polymorphs.

Conclusions:

• The new molecular-dynamics based approach offers an efficient way to search for and select stable crystal structures of molecular solids.
• This method shows promise for solving crystal structures from challenging or low-quality diffraction data.
• The technique is validated by its application to H2O-ice polymorphs.