Chemical Bonding - Everything a Chemist Wants to Know!?

Joachim Breternitz
Session 1 , Chemical Bonding
Monday, July 14, 2025
10:35 am

Joachim Breternitz^*

FH Münster University of Applied Sciences, Germany

e-mail: joachim.breternitz@fh-muenster.de

The different concepts of chemical bonding are not only relevant for molecular chemistry, but also for us materials chemists dealing with extended solids. I will highlight on an intriguing case, BeGeN2,[1] where computational bonding analysis delivered the answer as to why this compound has a unique crystal structure type and why regarding all bonds as simply ionic is chiefly too simple for many multinary compounds. While these analyses are currently based on DFT calculations and partitioning of computational charge density, I hope to trigger a debate, if quantum crystallography could play a pivotal role in the better understanding of bonding in (functional) materials.

References:

[1] J. Breternitz, Dalton Trans., 2025, 54, 5521-5525.

Data Quality

Crystallography has established a de-facto, well-understood, level of quality in its data over many decades. This is largely based on a long history of standardised instrumentation

Quantum crystallography and NMR crystallography

A weakness of current NMR crystallography for organic solids is the relatively poor positioning of H by independent atom modelling in XRD refinement. In order to obtain reasonable agreement with NMR data

Dynamic quantum crystallography – is it possible to obtain accurate thermodynamic properties from X-ray data?

Anisotropic displacement parameters usually do not attract attention and are treated as a dustbin for all experimental errors (there are only few remarkable exceptions). However, when data quality is good enough and we enrich the analysis of thermal motion in crystals with information from periodic DFT calculations