Bond analyses of borates from the Inorganic Crystal Structure Database

Area of Science:

• Inorganic Chemistry
• Materials Science
• Crystallography

Background:

• Oxoborates exhibit diverse crystal structures with dominant low-complexity fundamental building blocks (FBBs).
• Accurate bond-valence parameters (d(0)) are crucial for understanding chemical bonding in inorganic materials.
• The Inorganic Crystal Structure Database (ICSD) provides extensive crystallographic data.

Purpose of the Study:

• To calculate and recommend reliable bond-valence parameters (d(0)) for B-O bonds in oxoborates.
• To investigate the influence of FBB configurations on d(0) values.
• To establish a correlation between d(0) and nonlinear optical (NLO) properties for borate materials.

Main Methods:

• Utilized the bond-valence sum model to calculate d(0) for B-O bonds in 758 oxoborates.
• Analyzed the impact of FBBs, interstitial atoms, and anionic substitutions on d(0).
• Statistically calculated d(0) parameters for B-N, B-S, B-P, and B-F bonds.

Main Results:

• Calculated d(0) values show sensitivity to the detailed crystallographic structure and chemical bonding of boron atoms.
• Discrepancies in d(0) were observed due to interstitial atoms and anionic group substitutions.
• A linear relationship was identified between calculated NLO coefficients and d(0) values for various FBBs.

Conclusions:

• Recommended suitable d(0) data for diverse borate FBBs, particularly low-complexity ones.
• The d(0) parameter is a valuable tool for the preliminary investigation of borate NLO properties.
• This research facilitates efficient structural evaluation and design of novel borates with desired NLO characteristics.