Toward Crystal Structure Prediction for Conformationally Flexible Molecules:  The Headaches Illustrated by Aspirin

2004 ◽  
Vol 4 (6) ◽  
pp. 1119-1127 ◽  
Author(s):  
Carole Ouvrard ◽  
Sarah L. Price
Keyword(s):  
Crystal Structure ◽  
Structure Prediction ◽  
Crystal Structure Prediction ◽  
Flexible Molecules

scholarly journals Report on the sixth blind test of organic crystal structure prediction methods

2016 ◽  
Vol 72 (4) ◽  
pp. 439-459 ◽  
Author(s):  
Anthony M. Reilly ◽  
Richard I. Cooper ◽  
Claire S. Adjiman ◽  
Saswata Bhattacharya ◽  
A. Daniel Boese ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structure Prediction ◽  
Density Functional ◽  
Organic Crystal ◽  
Drug Candidate ◽  
Prediction Methods ◽  
Chloride Salt ◽  
Crystal Structure Prediction ◽  
Blind Test ◽  
Flexible Molecules

The sixth blind test of organic crystal structure prediction (CSP) methods has been held, with five target systems: a small nearly rigid molecule, a polymorphic former drug candidate, a chloride salt hydrate, a co-crystal and a bulky flexible molecule. This blind test has seen substantial growth in the number of participants, with the broad range of prediction methods giving a unique insight into the state of the art in the field. Significant progress has been seen in treating flexible molecules, usage of hierarchical approaches to ranking structures, the application of density-functional approximations, and the establishment of new workflows and `best practices' for performing CSP calculations. All of the targets, apart from a single potentially disorderedZ′ = 2 polymorph of the drug candidate, were predicted by at least one submission. Despite many remaining challenges, it is clear that CSP methods are becoming more applicable to a wider range of real systems, including salts, hydrates and larger flexible molecules. The results also highlight the potential for CSP calculations to complement and augment experimental studies of organic solid forms.

scholarly journals Validation of a search technique for crystal structure prediction of flexible molecules by application to piracetam

2005 ◽  
Vol 61 (5) ◽  
pp. 558-568 ◽  
Author(s):  
Harriott Nowell ◽  
Sarah L. Price
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Crystal Structures ◽  
Gas Phase ◽  
Intermolecular Interactions ◽  
Structure Prediction ◽  
Low Energy ◽  
Crystal Structure Prediction ◽  
New Approach ◽  
Flexible Molecules

A new approach to the crystal structure prediction of flexible molecules is presented. It is applied to piracetam, whose conformational polymorphs exhibit a variety of hydrogen-bond motifs but lack the intramolecular hydrogen bond found in the gas-phase ab initio optimized conformer. Stable crystal packing can result when favourable intermolecular interactions are made possible when the molecule distorts from the gas-phase conformation. If the resulting intermolecular lattice energy is sufficiently favourable to compensate for the intramolecular energy penalty associated with the suboptimal gas-phase conformation, then the crystal structure may be experimentally feasible. The new approach involves searching for low-energy crystal structures using a large number of rigid conformers, firstly to systematically explore which regions of conformational space could give rise to low-energy hydrogen-bonded crystal structures, and then to refine the search using crystallographic insight to optimize particular intermolecular interactions. The timely discovery of a new polymorph (form IV) by an independent experimental team allowed this approach to be validated by way of a `blind test' of crystal structure prediction. Form IV was successfully identified as the most favourable computed crystal structure with a conformation very distinct from that in the previously known polymorphs.

Crystal Structure Prediction via Deep Learning

2018 ◽  
Vol 140 (32) ◽  
pp. 10158-10168 ◽  
Author(s):  
Kevin Ryan ◽  
Jeff Lengyel ◽  
Michael Shatruk
Keyword(s):  
Crystal Structure ◽  
Deep Learning ◽  
Structure Prediction ◽  
Crystal Structure Prediction

scholarly journals New high-pressure phases of Fe7N3 and Fe7C3 stable at Earth's core conditions: evidences for carbon–nitrogen isomorphism in Fe-compounds

RSC Advances ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 3577-3581 ◽  
Author(s):  
Nursultan Sagatov ◽  
Pavel N. Gavryushkin ◽  
Talgat M. Inerbaev ◽  
Konstantin D. Litasov
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Ab Initio ◽  
Structure Prediction ◽  
Harmonic Approximation ◽  
Crystal Structure Prediction ◽  
Earth’S Core ◽  
Earth's Core ◽  
Core Conditions

We carried out ab initio calculations on the crystal structure prediction and determination of P–T diagrams within the quasi-harmonic approximation for Fe7N3 and Fe7C3.

scholarly journals Contact map based crystal structure prediction using global optimization

CrystEngComm ◽  
2021 ◽  
Author(s):  
Jianjun Hu ◽  
Wenhui Yang ◽  
Rongzhi Dong ◽  
Yuxin Li ◽  
Xiang Li ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Global Optimization ◽  
Crystal Engineering ◽  
Structure Prediction ◽  
Crystal Structure Prediction ◽  
New Materials ◽  
Contact Map

Crystal structure prediction is now playing an increasingly important role in the discovery of new materials or crystal engineering.

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