Experimental charge density studies: a tool for understanding the nature of interactions?

Maciej Kubicki

Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland

X-ray diffraction provides an insight into the electron density distribution in crystals. Standard methods are based on independent atom model (IAM) approximation, which assume the spherically-averaged, neutral atoms. This model is the basis of unprecedentent success of X-ray crystallography as a tool for “looking at the molecules”. However, the details of electron density distribution (bonding density, lone pairs etc.) are outside the possibilities of standard model.

The expansion of IAM into the non-sphercial ‘pseudoatom’ model allows to analyze the fine details of the electron density distribution. This procedure is highly demanding experimentally, but it offers – often together with Atoms-in-molecules approach – the possibility of deeper understanding of the nature of bonds and other interactions.

During the talk the general procedure will be described together with some results, ranging from small organic molecules to DNA and protein structures.