Journal ArticleDOI
SIR88 – a direct-methods program for the automatic solution of crystal structures
Maria Cristina Burla,Mercedes Camalli,Giovanni Luca Cascarano,C. Giacovazzo,Giampiero Polidori,Riccardo Spagna,D. Viterbo +6 more
TLDR
SIR88 as discussed by the authors is an integrated package of computer programs for the solution of crystal structures, based on the estimation of one-and two-phase structure seminvariants and three-and fourphase structure invariants according to the theory of representations.Abstract:
SIR88 is an integrated package of computer programs for the solution of crystal structures. The package is based on the estimation of one- and two-phase structure seminvariants and three- and four-phase structure invariants according to the theory of representations [Giacovazzo (1977). Acta Cryst. A33, 933–944; (1980). Acta Cryst. A36, 362–372]. The program works in all the space groups and in most cases it is able to provide the correct solution without user intervention. Some prior information like the availability of a partial structure or of pseudotranslational symmetry is easily exploited to obtain the structure solution.read more
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Journal ArticleDOI
SIR97: a new tool for crystal structure determination and refinement
Angela Altomare,Maria Cristina Burla,Mercedes Camalli,Giovanni Luca Cascarano,Carmelo Giacovazzo,Antonietta Guagliardi,Anna Moliterni,Giampiero Polidori,Riccardo Spagna +8 more
TL;DR: SIR97 is the integration of two programs, SIR92 and CAOS, the first devoted to the solution of crystal structures by direct methods, the second to refinement via least-squares–Fourier procedures.
Journal ArticleDOI
SIR2004: an improved tool for crystal structure determination and refinement
Maria Cristina Burla,Rocco Caliandro,Mercedes Camalli,Benedetta Carrozzini,Giovanni Luca Cascarano,Liberato De Caro,C. Giacovazzo,Giampiero Polidori,Riccardo Spagna +8 more
TL;DR: SIR2004 as mentioned in this paper is the evolution of the SIR2002 program, which is devoted to the solution of crystal structures by direct and Patterson methods, and it is able to solve ab initio both small/medium-size structures as well as macromolecules (up to 2000 atoms in the asymmetric unit).
Journal ArticleDOI
Ionic liquid crystals: hexafluorophosphate salts
TL;DR: A series of novel hexafluorophosphate salts, based on N,N′-dialkylimidazolium and substituted N-alkylpyridinium cations, display liquid crystalline behaviour at temperatures above their melting point as discussed by the authors.
Journal ArticleDOI
SIR2011: a new package for crystal structure determination and refinement
Maria Cristina Burla,Rocco Caliandro,Mercedes Camalli,Benedetta Carrozzini,Giovanni Luca Cascarano,Carmelo Giacovazzo,Mariarosaria Mallamo,Annamaria Mazzone,Giampiero Polidori,Riccardo Spagna +9 more
TL;DR: SIR2011, the successor of SIR2004, is the latest program of the SIR suite and can solve ab initio crystal structures of small- and medium-size molecules, as well as protein structures, using X-ray or electron diffraction data.
Journal ArticleDOI
A Contrivance for a Dynamic Porous Framework: Cooperative Guest Adsorption Based on Square Grids Connected by Amide−Amide Hydrogen Bonds
TL;DR: 3 subset 4Me(2)CO shows amorphous (nonporous)-to-crystal (porous) structural rearrangement in the Me( 2)CO adsorption and desorption process, where the framework of the 2-D motif is maintained.