Pillars of crystal engineering: crystal energies and symmetry operators

CrystEngComm ◽  
2018 ◽  
Vol 20 (18) ◽  
pp. 2511-2518 ◽  
Author(s):  
A. Gavezzotti

Molecular pairs with top-ranking interaction energy are sorted out for 1235 organic crystal structures, in relationship with the corresponding symmetry operators. Top pairing energies compare with 20–40% of the total lattice energies (see figure).

Author(s):  
Srinu Tothadi ◽  
Gautam R. Desiraju

The idea of a structural landscape is based on the fact that a large number of crystal structures can be associated with a particular organic molecule. Taken together, all these structures constitute the landscape. The landscape includes polymorphs, pseudopolymorphs and solvates. Under certain circumstances, it may also include multi-component crystals (or co-crystals) that contain the reference molecule as one of the components. Under still other circumstances, the landscape may include the crystal structures of molecules that are closely related to the reference molecule. The idea of a landscape is to facilitate the understanding of the process of crystallization. It includes all minima that can, in principle, be accessed by the molecule in question as it traverses the path from solution to the crystal. Isonicotinamide is a molecule that is known to form many co-crystals. We report here a 2:1 co-crystal of this amide with 3,5-dinitrobenzoic acid, wherein an unusual N−H⋯N hydrogen-bonded pattern is observed. This crystal structure offers some hints about the recognition processes between molecules that might be implicated during crystallization. Also included is a review of other recent results that illustrate the concept of the structural landscape.


Tetrahedron ◽  
1999 ◽  
Vol 55 (50) ◽  
pp. 14301-14322 ◽  
Author(s):  
Lawrence J. Williams ◽  
B. Jagadish ◽  
Michael G. Lansdown ◽  
Michael D. Carducci ◽  
Eugene A. Mash

2001 ◽  
Vol 1 (3) ◽  
pp. 191-194 ◽  
Author(s):  
Giannis S. Papaefstathiou ◽  
Alexandros Tsohos ◽  
Catherine P. Raptopoulou ◽  
Aris Terzis ◽  
Vassilis Psycharis ◽  
...  

2019 ◽  
Vol 75 (12) ◽  
pp. 1952-1952
Author(s):  
Ligia R. Gomes ◽  
John Nicolson Low ◽  
James L. Wardell ◽  
Camila Capelini ◽  
José Daniel Figueroa Villar ◽  
...  

In the paper by Gomes et al. [Acta Cryst. (2019), E75, 1403–1410], there was an error and omission in the author and affiliation list.


CrystEngComm ◽  
2021 ◽  
Author(s):  
Guo-Jun Yuan ◽  
Hong Zhou ◽  
Li Li ◽  
Hong Chen ◽  
Xiaoming Ren

Crystal engineering study aims at a better understanding of the correlation between the components and crystal structures, so that the desired crystal structure and functionality will be acquired. In this...


2019 ◽  
Vol 234 (10) ◽  
pp. 671-683 ◽  
Author(s):  
Alexandru Turza ◽  
Maria O. Miclăuș ◽  
Aurel Pop ◽  
Gheorghe Borodi

Abstract Androsta-1,4-dien-17β-ol-3-one, also known as boldenone, is an anabolic-androgenic steroid derived from testosterone. The crystal structures of boldenone base, boldenone acetate, boldenone propionate, boldenone cypionate and a boldenone acetate polymorph obtained by high throughput screening were investigated. Hirshfeld surfaces and fingerprint plots breakdown revealed that the molecular packing in the crystals are driven by dominant H⋯H intermolecular contacts, followed by O⋯H/H⋯O contacts and to a lesser degree C⋯H/H⋯C contacts. The steroid skeleton rings, for all the reported compounds, adopt the following conformation: planar in A, chair in B and C, whereas C(13) envelope conformations are found for the five-membered D rings. The total lattice energies were calculated as a sum of four terms (Coulombic, polarization, dispersion, repulsion).


2020 ◽  
Vol 76 (6) ◽  
pp. 630-651
Author(s):  
Daniel Nguyen ◽  
Piero Macchi ◽  
Anatoliy Volkov

The previously reported exact potential and multipole moment (EP/MM) method for fast and accurate evaluation of the intermolecular electrostatic interaction energies using the pseudoatom representation of the electron density [Volkov, Koritsanszky & Coppens (2004). Chem. Phys. Lett. 391, 170–175; Nguyen, Kisiel & Volkov (2018). Acta Cryst. A74, 524–536; Nguyen & Volkov (2019). Acta Cryst. A75, 448–464] is extended to the calculation of electrostatic interaction energies in molecular crystals using two newly developed implementations: (i) the Ewald summation (ES), which includes interactions up to the hexadecapolar level and the EP correction to account for short-range electron-density penetration effects, and (ii) the enhanced EP/MM-based direct summation (DS), which at sufficiently large intermolecular separations replaces the atomic multipole moment approximation to the electrostatic energy with that based on the molecular multipole moments. As in the previous study [Nguyen, Kisiel & Volkov (2018). Acta Cryst. A74, 524–536], the EP electron repulsion integral is evaluated analytically using the Löwdin α-function approach. The resulting techniques, incorporated in the XDPROP module of the software package XD2016, have been tested on several small-molecule crystal systems (benzene, L-dopa, paracetamol, amino acids etc.) and the crystal structure of a 181-atom decapeptide molecule (Z = 4) using electron densities constructed via the University at Buffalo Aspherical Pseudoatom Databank [Volkov, Li, Koritsanszky & Coppens (2004). J. Phys. Chem. A, 108, 4283–4300]. Using a 2015 2.8 GHz Intel Xeon E3-1505M v5 computer processor, a 64-bit implementation of the Löwdin α-function and one of the higher optimization levels in the GNU Fortran compiler, the ES method evaluates the electrostatic interaction energy with a numerical precision of at least 10−5 kJ mol−1 in under 6 s for any of the tested small-molecule crystal structures, and in 48.5 s for the decapeptide structure. The DS approach is competitive in terms of precision and speed with the ES technique only for crystal structures of small molecules that do not carry a large molecular dipole moment. The electron-density penetration effects, correctly accounted for by the two described methods, contribute 28–64% to the total electrostatic interaction energy in the examined systems, and thus cannot be neglected.


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