Commission on Quantum Crystallography

Current Projects

Round robin on charge density using synchrotron radiation

A round robin test on charge density studies on a molecular compound using synchrotron radiation was undertaken in 2012 in collaboration with the Commission on Synchrotron Radiation.

The chosen compound is a molecule-based compound, the manganese formate dihydrate, Mn(HCOO)2(H2O)2, for which several data collections on different SR beamlines (APS, DESY) and conventional X-ray sources are already available from Prof. Bo Iversen (Denmark) who agreed to share his data for the project. The test involves three synchrotron groups at Spring-8 (Japan), APS (USA) and Soleil (France) and four groups working with conventional sources in France, Germany, UK and Canada. Crystal batches were prepared at the LMI (Laboratory of Materials and Interfaces), Lyon University (France) for distribution to the different groups.

The various measured data sets will be transmitted to Jacob Overgaard (Univ. Aarhus, Denmark) who will perform the charge density refinement on each data set in a systematic way in order to enable a valuable comparison.

Electron distribution in the metallic bond by QCBED techniques and X-ray diffraction

Dr P. Nakashima (Monash University, Australia) -

The CSMD Commission and the Commission on Electron Crystallography decided to jointly support in 2012 an IUCr project on electron distribution in the metallic bond by QCBED techniques and X-ray diffraction, proposed by Dr P. Nakashima (Monash University, Australia). Dr P. Nakashima is leading the project. The work was organized as following: distribute the metals to the six different involved groups in Norway, Germany, USA, Japan and Australia (two groups for each metal) and meet once a year (during 3 years).

Past Projects 

Constrained Experimental Wavefunction

D. Jayatilaka (UWA, Perth, Australia) -

This project began in 2005 and was achieved in 2011. It concerns the possibility of extracting wavefunctions from the accurate X-ray and polarized neutron experimental data. Or, said in other words, to get theoretical density matrices suitably modified to fit the results of (a number of) experiment(s). This project was launched during the 2004 Gordon Research Conference (GRC). Seven groups were participating and results were reported during the Madrid 2011 IUCr Congress.

These pages are maintained by the Commission Last updated: 15 Oct 2021