Radiation damage in X-ray crystallography: a quantum-mechanical study of photoinduced defect formation in beeswax-analogue n-eicosane crystals

2016 ◽  
Vol 135 (2) ◽  
Author(s):  
Leonardo Bernasconi ◽  
José Brandao-Neto
Author(s):  
Franco Cristiani ◽  
Francesco Demartin ◽  
Francesco A. Devillanova ◽  
Franceso Isaia ◽  
Giuseppe Saba ◽  
...  

2008 ◽  
Vol 462 (4-6) ◽  
pp. 158-163 ◽  
Author(s):  
Bruno Pagano ◽  
Michele Pavone ◽  
Anna Lisa Piccinelli ◽  
Luca Rastrelli ◽  
Osmany Cuesta-Rubio ◽  
...  

2010 ◽  
Vol 493 (1-3) ◽  
pp. 151-157 ◽  
Author(s):  
Abir Bhattacharya ◽  
Soumen Ghosh ◽  
Kavitha Kankanala ◽  
Vangala Ranga Reddy ◽  
Khagga Mukkanti ◽  
...  

2008 ◽  
Vol 6 (4) ◽  
pp. 542-548 ◽  
Author(s):  
Rafal Kruszynski

Abstract2,4-dinitrophenylhydrazine hydrochloride hydrate (I) was determined by X-ray crystallography, and the intermolecular interaction energies were calculated in terms of Natural Bond Orbital analysis. The asymmetric unit of (I) consists of a dinitrophenylhydrazinium cation, a chloride anion and a water molecule. The interatomic distances and angles in (I) show no unusual values. In the structure there are intermolecular N—H⊎⊎⊎O, N—H⊎⊎⊎Cl, O—H⊎⊎⊎Cl, C—H⊎⊎⊎O hydrogen bonds with bonding energy ranging form 16.03 to 0.76 kcal mol−1. These hydrogen bonds create the following N1 motifs: 6D, S(5), S(6), C(6), C(9). N1D motifs become infinite at the third level and are 2C 32(6), C 32(7).


2004 ◽  
Vol 68 (5) ◽  
pp. 819-824 ◽  
Author(s):  
B. Winkler ◽  
V. Milman ◽  
C. J. Pickard

AbstractWe have studied the structures of Al/Si disordered leucite and bicchulite with a quantum mechanical version of the virtual crystal approximation, VCA. In leucite, the average tetrahedron has a composition of (AlSi2)O4, while bicchulite represents an extreme case with (Al2Si)O4 tetrahedra. Both structures are well described with the VCA. In conjunction with an earlier study, where we have shown that the (AlSi)O4 tetrahedra in gehlenite and Al,Si-disordered octahedra are also well reproduced, we have now established that the VCA gives a reliable description of the averaged structure of disordered aluminosilicates over the whole compositional range. The current calculations confirm that Al/Si ordering is not driving the cubic to tetragonal phase transformation in leucite. In bicchulite, the model calculations are consistent with hydrogen on Wyckoff position 8c, in agreement with the result of a single crystal X-ray diffraction study, but in variance with results based on a neutron powder diffraction study.


2003 ◽  
Vol 107 (13) ◽  
pp. 2910-2920 ◽  
Author(s):  
Jérôme Rose ◽  
Theodorus J. M. De Bruin ◽  
Guy Chauveteau ◽  
René Tabary ◽  
Jean-Louis Hazemann ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document