structure_time_scaleStructures on different time scales
Theo Woike, Dominik Schaniel (Eds.)Structures on different time scales March 2018

The book « Structures on different time scales » presents theory and methods to study the structure of condensed matter on different time scales. The authors cover the structure analysis by X-ray diffraction methods from crystalline to amorphous materials, from static-relaxed averaged structures to short-lived electronically excited structures, including detailed descriptions of the time-resolved experimental methods. Complementary, an overview of the theoretical description of condensed matter by static and time-dependent density functional theory is given, starting from the fundamental quantities that can be obtained by these methods through to the recent challenges in the description of time-dependent phenomena such as optical excitations.

With contributions from R. B. Neder, K. Schwarz & P. Blaha, V. Olevano, S. Pillet, B. D. Patterson.



acta-cryst-bEuropean Journal of Inorganic Chemistry Volume 2018, Issue 3-4, January 2018

Guest Editors Boris Le Guennic, Guillaume Chastanet, Sébastien Pillet, and Rodolphe Clérac emphasize the pivotal role of Olivier Kahn in the field of molecular magnetism, presenting this issue in honor of his valuable contribution.





faraday_discToward a reverse hierarchy of halogen bonding between bromine and iodine
Emmanuel Aubert, Enrique Espinosa, Irène Nicolas, Olivier Jeannin and Marc Fourmigué Faraday Discussions Volume 203, October 2017

We compare here the halogen bond characteristics of bimolecular adducts involving either N-bromo- or N-iodosaccharin as strong halogen bond donors, with 4-picoline as a common XB acceptor. In the NBSac$Pic system, the bromine atom of NBSac is displaced toward the picoline, almost at a median position between the two nitrogen atoms, NSac and N0 Pic, with NSac/Br and Br/N0 Pic distances at 2.073(6) and 2.098(6) °A respectively. This extreme situation contrasts with the analogous iodine derivative, NISac$Pic, where the NSac–I and I/N0 Pic distances amount to 2.223(4) and 2.301(4) °A respectively. Periodic DFT calculations, and molecular calculations of adducts (PBEPBE-D2 aug-cc-pVTZ) either at the experimental frozen geometry or with optimization of the halogen position, indicate a more important degree of covalency (i.e. shared-shell character) in the adduct formed with the bromine atom. A stronger charge transfer to the picoline is also found for the bromine (+0.27 |e|) than for the iodine (+0.18 |e|) system. This inversion of halogen bond strength between I and Br finds its origin in the strong covalent character of the interaction in these adducts, in line with the strength of covalent N–Br and N–I bonds.


acta-cryst-bThe August 2017 special issue pf Acta Crystallographica B on charge density, photocrystallography and time-resolved crystallography: a tribute to Professor Philip Coppens (Guest Editors: Claude Lecomte, Jason Benedict and Yu-Sheng Chen) is dedicated to a lifetime of outstanding scientific achievements by Professor Philip Coppens.
Acta Crystallographica B Special Issue, August 2017

The members of the CRM2 laboratory contributed with various articles in the field of electron density analysis and time-resolved photocrystallography to this issue in remembrance of the impactful scientific legacy of Philip Coppens.

Cover illustration: Images illustrating charge and spin density, and photocrystallography taken from Voufack et al. [(2017). Acta Cryst. B73, 544-549], Mariette et al. [(2017). Acta Cryst. B73, 660-668] and Stachowicz et al. [(2017). Acta Cryst. B73, 643-653].


acta-cryst-bKeynote Lecture: Crystallographic rationale for the formation of twinned crystals by Massimo Nespolo
Massimo Nespolo IUCr 2017 August 2017







inocajElastic Frustration Triggering Photoinduced Hidden Hysteresis and Multistability in a Two-Dimensional Photoswitchable Hofmann-Like Spin-Crossover Metal–Organic Framework
Eric Milin, Véronique Patinec, Smail Triki, El-Eulmi Bendeif, Sébastien Pillet, Mathieu Marchivie, Guillaume Chastanet, and Kamel Boukheddaden Inorganic Chemistry Volume 55 (22), 11652–11661, July 2016

We report a new two-dimensional Hofmann-like spin-crossover material that experiences strong elastic frustration, leading to an incomplete spin transition. Under light, a hidden stable low-spin state is reached, revealing the existence of a hidden thermal hysteresis and multistability features. These characteristics pave the way for a multidirectional photoswitching and allow potential applications for electronic devices based on ternary digits.



acta-cryst-bCharge distribution as a tool to investigate structural details. IV. A new route to heteroligand polyhedra
Massimo Nespolo Acta Crystallographica B Volume 72, Issue 1, 51-66, February 2016

The structure of crocoite in the anion-centred description. The Charge Distribution (CHARDI) analysis shows that the structure can be described as centred on cation-centred homoligand polyhedra or anion-centred heteroligand polyhedra.




zeitSpecial Issue: Mathematical Crystallography / Guest Editors: Massimo Nespolo and Mois Aroyo
Massimo Nespolo Zeitschrift für Kristallographie Volume 230, Issue 13, 2015





crystal-coverTips and traps on crystal twinning: how to fully describe your twin
Massimo Nespolo Crystal Research and Technology Volume 50, Issue 5, 362–371, May 2015

Derivation of the symmetry of the (011) twin in cassiterite in stereographic projection. H1 and H2 are the symmetry elements of the 4/mmm point group along the a axis for the two individuals, the red line is the twin plane, H* is the intersection group, K is the twin point group obtained as extension of H* by the twin plane.




paradoxThe Paradox of Hydrogen-Bonded Anion−Anion Aggregates in Oxoanions: A Fundamental Electrostatic Problem Explained in Terms of Electrophilic···Nucleophilic Interactions

I. Mata, E. Molins, I. Alkorta, and E. Espinosa, J. Phys. Chem. A (2015),119, 183–194.

Le paradoxe des agrégats anioniques : Un problème électrostatique expliqué à partir des interactions électrophile…nucléophile




cocrystalCocrystal or Salt: Solid State-Controlled Iodine Shift in Crystalline Halogen-Bonded Systems

Makhotkina, O., Lieffrig, J., Jeannin, O., Fourmigué, M., Aubert, E. & Espinosa, E Crystal Growth & Design (2015), 15, 3464-3473

Effet de l’environnement cristallin sur l’intensité et la nature des interactions intermoléculaires




iucrjMultiple light-induced NO linkage isomers in the di­nitrosyl complex [RuCl(NO)2(PPh3)2]BF4 unravelled by photocrystallographic and IR analysis
N. Casaretto, S. Pillet, E.-E. Bendeif, D. Schaniel, A. K. E. Gallien, P. Klüfers and T. Woike, IUCr J., (2015), 2, 35-44

Une photo-isomérisation sélective d’un seul ligand nitrosyl a été caractérisée pour la première fois dans un complexe dinitrosyl, en combinant des expériences de photo-cristallographique et de spectroscopie infrarouge. Plusieurs photo-isomères ont ainsi été détectés, et leur signature spectrale déterminée.

Commentaire scientifique par P. R. Raithby: Photocrystallography reveals new metastable nitrosyl linkage isomers in the solid state. (2015) IUCrJ 2, 5-6

Détecteurs à pixels hybrides : un nouvel outil pour mesurer la structure électronique des solides cristallins

Des physiciens ont réalisé le premier diffractomètre à rayons X de laboratoire mettant en œuvre un détecteur à pixels hybrides. L’amélioration de la sensibilité en intensité qui en résulte permet une reconstitution deux fois plus précise des structures électroniques des solides cristallisés.
XPAD X-ray hybrid pixel detector for charge density quality diffracted intensities on laboratory equipment
E. Wenger, S. Dahaoui, P. Alle, P. Parois, C. Palin, C. Lecomte et D. Schaniel Acta Crystallographica B70, 783-791 (2014)

Commentaire scientifique par D. Stalke: A hybrid pixel detector at an in-house device generating stunning charge density quality data; Acta Cryst. (2014). B70, 781-782
Voir aussi les actualités de la recherche CNRS

mathcrystSpecial Issue: Mathematical Crystallography / Guest Editors: Massimo Nespolo and Gregory McColm
Massimo Nespolo Acta Crystallographica Section A Special issue, December 2014






detecteur-pixelRoom temperature bistability with wide thermal hysteresis in a spin crossover silica nanocomposite
P. Durand, S. Pillet, E.-E. Bendeif, C. Carteret, M. Bouazaoui, H. El Hamzaoui, B. Capoen, L. Salmon, S. Hébert, J. Ghanbaja, L. Aranda and D. Schaniel, J. Mater. Chem. C, (2013), 1, 1901

Une bistabilité à température ambiante a été obtenue pour un nanocomposite élaboré par croissance confinée de nanoparticules à transition de spin [Fe(Htrz)2(trz)](BF4) au sein d’une matrice mésoporeuse de silice de porosité parfaitement contrôlée. Les nanoparticules monodisperses de diamètre 3.5nm présentent l’hystérèse la plus large (65K) jamais atteinte pour des particules de cette taille.




halogenCharge-Assisted Halogen Bonding: Donor-Acceptor Complexes with Variable Ionicity

J. Lieffrig, O. Jeannin, A. Frackowiak, I. Olejniczak, R. Swietlik, S. Dahaoui, E. Aubert, E. Espinosa, P. Auban-Senzier and M. Fourmigué Chemistry: a European Journal (2013), 19, 14804-14813.

Ingénierie Cristalline appliquée à la Science de Matériaux : Le contrôle des propriétés électroniques de composés à transfert de charge par le contrôle de l’intensité de la liaison halogène entre cations et anions.




chalcogenChalcogen bonding: Experimental and theoretical determinations from electron density analysis. Geometrical preferences driven by electrophilic-nucleophilic interactions

Brezgunova M. E., Lieffrig, J., Aubert, E., Dahaoui, S., Fertey, P., Lebègue, S., Angyan, J. G., Fourmigué, M. & Espinosa, E. Crystal Growth & Design (2013), 13, 3283-3289

Etudes sur l’orientation relative de molécules dans l’espace cristallin et leurs intensités d’interaction