Natalie Haarer

Oct 042019
 

Natalie is implementing a scattering model for chemical groups which behave as “hindered rotors” to the base Fortran code of the CRYSTALS software. The representation requires fewer parameters and is more physically realistic than current models. Look out for better trifluoromethyl groups in future!

Natalie does not have a favourite programming language, believing instead that we should use the appropriate tool for the problem being solved. In her spare time she is a keen cross-country runner and has completed over 170 parkruns.

ECM31, Oviedo and ECA Crystallographic Computing School, Mieres

Aug 292018
 

The 31st European Crystallography Meeting was held in Oviedo, Spain from 22-26 August 2018.

During the meeting George Sackman presented a poster (MS10-P05) on recent neutron diffraction work with Richard Cooper and Alison Edwards: Disordered or not: A cautionary tale when inferring proton disorder solely from X-ray and computational data.

Richard Cooper gave a presentation (GI-MS47-O5) in the Saturday afternoon session How to… take your next steps in crystallography, based on experience of a career which despite including several areas of science and organisations rarely strayed outside the OX postcode.

On Sunday afternoon Amber Thompson presented (MS27-O5) Adventures in modulation: derivatives of Barluenga’s reagent, including work from Lewis Morgan, Yejin Kim, Emma McKinley, Jack Blandy, Claire Murray and Kirsten Christensen, in the session Quasicrystals: theory and
experiment.

Prior to the meeting, Richard Cooper was a tutor at the ECA Crystallographic Computing School in Mieres, organised by the ECA SIG 9 and gave a lecture on Programming Crystallographic Symmetry.

Prizes at the BCA Spring Meeting

Apr 052018
 

Kiaora Tolmie recieving the CCG Poster PrizeThe 2018 Meeting of the British Crystallographic Association was held at Warwick University where Chem. Cryst. was well represented.  The meeting started with the Young Crystallographers Satellite meeting, during which Lewis Morgan’s oral presentation was so “eggsellent” that he won the Industrial Group Prize for the best talk, and with it, the dubious honour of presenting it again as a plenary in the main meeting.

At the conference dinner Kiaora Tolmie received a CCG CrystEngComm poster prize for her poster on hard-to-crystallize materials, and James Bird was awarded the YCG I’m-a-scientist-get-me-out-of here prize for the poster presenter who most clearly and enthusiastically communicated their results.

Congratulations to all three winners!

 

Lewis Morgan delivering his prize-winning presentation at the BCA Spring Meeting 2018

Lewis Morgan delivering his prize-winning presentation

 

A full list of the presentations from Chem. Cryst.:

George A. Sackman & Richard I. Cooper
Distinguishing Disorder: A Molecular Dynamics Approach (Poster Presentation)

Kiaora L. M. Tolmie & Richard I. Cooper
Structure Determination of Hard-to-Crystallize Materials (Poster Presentation)

Lewis C. F. Morgan, Jack N. Blandy, Claire A. Murray, Kirsten E. Christensen & Amber L. Thompson
Improving Our Understanding of Modulation in Molecular Materials (Poster & Oral Presentation)

James M. Bird & Richard I. Cooper
A Comparison of Molecular Dynamics Techniques for Simulation of Thermal Disorder in Molecular Crystals (Poster Presentation)

Oliver J. A. Bar & Richard I. Cooper
A Study of Phase Transitions in Organic and Metal-organic Inclusion Complexes through Molecular Dynamics Simulation (Poster Presentation)

Richard I. Cooper
CrysPy: CRYSTALS in Python (Poster Presentation)

Amber L. Thompson
When are Bad Data Good Data? (Keynote Oral Presentation)

HUG and SQUEEZE: using CRYSTALS to incorporate resonant-scattering in the SQUEEZE structure factor contributions to determine absolute structure

Oct 232017
 

Acta Crystallographica, 2017, C73, 845–853. [ doi:10.1107/S2053229617013304 ]

Using an approximate correction to the X-ray scattering from disordered, resonantly scattering regions of crystal structures we have developed and tested a procedure (HUG) to recover the absolute structure using conventional Flack x refi nement or other post-re finement determination methods.

2016 British Crystallographic Association Meeting

Apr 082016
 

group16The 2016 British Crystallographic Meeting Spring Meeting took place at the University of Nottingham from 4th – 7th April. Contributions from Chem. Cryst. staff and students were:

Jerome G. P. Wicker, Bill I. F. David & Richard I. Cooper
When will it Crystallise? (Talk in session: From Amorphous to Crystal)

Jo Baker & Richard I. Cooper
Making and Measuring Photoswitchable Materials (Talk in session: Young Crystallographers’ Satellite)

Pascal Parois, Karim J. Sutton & Richard I. Cooper
On the application of leverage analysis to parameter precision using area detector strategies (Poster)

Oliver Robshaw & Richard I. Cooper
The role of molecular similarity in crystal structure packing (Poster)

Katie McInally & Richard I. Cooper
Linking crystallization prediction, theory and experiment using solubility curve determination (Poster)

Richard I. Cooper, Pascal Parois & David J. Watkin
Non-routine single crystal structure analyses using CRYSTALS (Poster)

Alex Mercer & Richard I. Cooper
Fitting Disordered Crystal Structures by Simulated Annealing of an Ensemble Model (Poster)

 

Structure of the Month – September 2012

Sep 042012
 

Presented by: Sebastian D. Pike & Dr. Amber L. Thompson
Research Leader: Prof. Andrew S. Weller
Published: Science

Transition metal σ-alkane complexes are key intermediates in catalytic C–H activation processes. We have used a direct crystal to crystal transition, by reaction with H2, to produce an alkane σ-complex directly.  This structure is of an alkane (norbornane, NBA) σ-bound to a d8–Rh(I) metal centre, in which the chelating alkane ligand is coordinated to the pseudo-square planar metal centre through two σ-C–H bonds. Although disordered (inset), the structure was refined without restraints for the coordinated NBA. The complex reacts further over time, so many attempts were required to “catch” the crystal free from both starting material and final product.

Structure of the Month – September 2012

Structure of the Month – September 2012

Alkyl-chain Disorder in Tetraisohexylammonium Bromide

Mar 192012
 

Acta Cryst.  (2012), C68, o152-o155.    [ doi:10.1107/S0108270112009377 ]

Tetraisohexylammonium bromide [systematic name: tetrakis(4-methylpentyl)azanium bromide], C24H52N+·Br–, is a powerful structure II clathrate hydrate crystal-growth inhibitor. The crystal structure, in the space group P3221, contains one ammonium cation and one bromide anion in the asymmetric unit, both on general positions. At 100 K, the ammonium cation exhibits one ordered isohexyl chain and three disordered isohexyl chains. At 250 K, all four isohexyl chains are disordered. In an effort to reduce the disorder in the alkyl chains, the crystal was thermally cycled, but the disorder remained, indicating that it is dynamic in nature.

Tetraisohexylammonium Bromide

Tetraisohexylammonium Bromide

Electronic reprints

  • Oxford University Research Archive [direct pdf]

Publisher’s copy