Crystal morphology prediction and morphology variation in NaIO4 and NaIO4.3H2O

Area of Science:

• Crystallography
• Computational Chemistry
• Materials Science

Background:

• Predicting crystal morphology is crucial for understanding material properties.
• Computational methods, like attachment energy calculations, are increasingly used for morphology prediction.
• Sodium iodate (NaIO(4)) and its hydrate (NaIO(4).3H(2)O) are water-soluble ionic compounds with interesting crystallographic features.

Purpose of the Study:

• To predict the crystal morphologies of sodium iodate (NaIO(4)) and sodium iodate trihydrate (NaIO(4).3H(2)O) using computational methods.
• To investigate the relationship between early growth and mature crystal morphologies in these systems.
• To explore the influence of factors like hydrogen bonding and solvent desorption on crystal growth.

Main Methods:

• Attachment energies were computed using only Coulomb potentials.
• Morphology prediction was performed by adjusting a single attachment energy value for each system.
• The computational predictions were compared with observed crystal morphologies.

Main Results:

• A systematic relationship between early growth and mature crystal morphologies was identified for both NaIO(4) and NaIO(4).3H(2)O.
• Adjusting one attachment energy value successfully reproduced the observed crystal morphologies for both compounds.
• The study highlighted the importance of considering solvent desorption for NaIO(4) morphology and hydrogen bonding for NaIO(4).3H(2)O.

Conclusions:

• Computational prediction of crystal morphology using Coulombic attachment energies is effective for sodium iodate and its hydrate.
• A single adjustable parameter can reconcile early and mature crystal growth predictions.
• The findings provide insights into the crystallization mechanisms of water-soluble ionic compounds, including polar crystals with extensive hydrogen bonding.