Archive for the ‘Chemical IT’ Category

FAIR data ⇌ Raw data.

Thursday, December 7th, 2017
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FAIR data is increasingly accepted as a description of what research data should aspire to; Findable, Accessible, Inter-operable and Re-usable, with Context added by rich metadata (and also that it should be Open). But there are two sides to data, one of which is the raw data emerging from say an instrument or software simulations and the other in which some kind of model is applied to produce semi- or even fully processed/interpreted data. Here I illustrate a new example of how both kinds of data can be made to co-exist.

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PIDapalooza 2018: the open festival for persistent identifiers.

Tuesday, November 14th, 2017
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PIDapalooza is a new forum concerned with discussing all things persistent, hence PID. You might wonder what possible interest a chemist might have in such an apparently arcane subject, but think of it in terms of how to find the proverbial needle in a haystack in a time when needles might look all very similar. Even needles need descriptions, they are not all alike and PIDs are a way of providing high quality information (metadata) about a digital object.  

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VSEPR Theory: Octet-busting or not with trimethyl chlorine, ClMe3.

Sunday, November 12th, 2017
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A few years back, I took a look at the valence-shell electron pair repulsion approach to the geometry of chlorine trifluoride, ClF3 using so-called ELF basins to locate centroids for both the covalent F-Cl bond electrons and the chlorine lone-pair electrons. Whereas the original VSEPR theory talks about five “electron pairs” totalling an octet-busting ten electrons surrounding chlorine, the electron density-based ELF approach located only ~6.8e surrounding the central chlorine and no “octet-busting”. The remaining electrons occupied fluorine lone pairs rather than the shared Cl-F regions. Here I take a look at ClMe3, as induced by the analysis of SeMe6.

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Two stories about Open Peer Review (OPR), the next stage in Open Access (OA).

Thursday, October 5th, 2017
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We have heard a lot about OA or Open Access (of journal articles) in the last five years, often in association with the APC (Article Processing Charge) model of funding such OA availability. Rather less discussed is how the model of the peer review of these articles might also evolve into an Open environment. Here I muse about two experiences I had recently.

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Accessing (raw) chemical data: a peek into the CIF format.

Friday, July 21st, 2017
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There is much focus at the moment on how to ensure experimental replicability in e.g. the molecular sciences. An important aspect of that is having access to FAIR data; data which is findable, accessible, inter-operable and re-usable. One of the “gold standards” in chemistry is the data associated with crystal structures. Here I take an inside peek into the standard file-type for carrying crystal structure data, the CIF file (the Crystallographic Information File).

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How to search data repositories for FAIR chemical content and data: SubjectScheme

Thursday, June 8th, 2017
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As data repositories start to flourish, it is reasonable to ask questions such as what sort of chemistry can be found there and how can I find it? Here I give an updated[1] worked example of a digital repository search for chemical content and also pose an important issue for the chemistry domain.

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References

  1. H.S. Rzepa, A. Mclean, and M.J. Harvey, "InChI As a Research Data Management Tool", Chemistry International, vol. 38, 2016. http://dx.doi.org/10.1515/ci-2016-3-408

FAIR Research data: Gravitational waves as an example from the astrophysics community.

Friday, June 2nd, 2017
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In 2016, the world heard that gravitational waves had been detected and now a third instance is reported. Given that the data associated with these detections are perhaps amongst the most important instances in recent times, I thought I might take a peek at how it was managed.

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Tautomeric polymorphism.

Thursday, June 1st, 2017
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Conformational polymorphism occurs when a compound crystallises in two polymorphs differing only in the relative orientations of flexible groups (e.g. Ritonavir). At the Beilstein conference, Ian Bruno mentioned another type;  tautomeric polymorphism, where a compound can crystallise in two forms differing in the position of acidic protons. Here I explore three such examples.

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Challenges in reliably representing the chemistry of crystal structures.

Monday, May 29th, 2017
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The title here is taken from a presentation made by Ian Bruno from CCDC at the recent conference on Open Science. It also addresses the theme here of the issues that might arise in assigning identifiers for any given molecule.

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Curating a nine year old journal FAIR data table.

Monday, May 29th, 2017
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As the Internet and its Web-components age, so early pages start to decay as technology moves on. A few posts ago, I talked about the maintenance of a relatively simple page first hosted some 21 years ago. In my notes on the curation, I wrote the phrase “Less successful was the attempt to include buttons which could be used to annotate the structures with highlights. These buttons no longer work and will have to be entirely replaced in the future at some stage.” Well, that time has now come, for a rather more crucial page associated with a journal article published more recently in 2009.[1]

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References

  1. H.S. Rzepa, "Wormholes in chemical space connecting torus knot and torus link π-electron density topologies", Phys. Chem. Chem. Phys., vol. 11, pp. 1340-1345, 2009. http://dx.doi.org/10.1039/b810301a