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Шаблон:Infobox biodatabase The Cambridge Structural Database (CSD) is both a repository and a validated and curated resource for the three-dimensional structural data of molecules generally containing at least carbon and hydrogen, comprising a wide range of organic, metal-organic and organometallic molecules. The specific entries are complementary to the other crystallographic databases such as the Protein Data Bank (PDB), Inorganic Crystal Structure Database and International Centre for Diffraction Data. The data, typically obtained by X-ray crystallography and less frequently by electron diffraction or neutron diffraction, and submitted by crystallographers and chemists from around the world, are freely accessible (as deposited by authors) on the Internet via the CSD's parent organization's website (CCDC, Repository[1]). The CSD is overseen by the not-for-profit incorporated company called the Cambridge Crystallographic Data Centre, CCDC.

Файл:The inside of the CCDC headquarters Cambridge, UK.jpg
The inside of the CCDC headquarters Cambridge, UK

The CSD is a widely used repository for small-molecule organic and metal-organic crystal structures for scientists. Structures deposited with Cambridge Crystallographic Data Centre (CCDC) are publicly available for download at the point of publication or at consent from the depositor. They are also scientifically enriched and included in the database used by software offered by the centre. Targeted subsets of the CSD are also freely available to support teaching and other activities.[2]

History

The CCDC grew out of the activities of the crystallography group led by Olga Kennard OBE FRS in the Department of Organic, Inorganic and Theoretical Chemistry of the University of Cambridge. From 1965, the group began to collect published bibliographic, chemical and crystal structure data for all small molecules studied by X-ray or neutron diffraction. With the rapid developments in computing taking place at this time, this collection was encoded in electronic form and became known as the Cambridge Structural Database (CSD).

The CSD was one of the first numerical scientific databases to begin operations anywhere in the world, and received academic grants from the UK Office for Scientific and Technical Information and then from the UK Science and Engineering Research Council. These funds, together with subventions from National Affiliated Centres, enabled the development of the CSD and its associated software during the 1970s and 1980s. The first releases of the CSD System to the United States, Italy and Japan occurred in the early 1970s. By the early 1980s the CSD System was being distributed in more than 30 countries. As of 2014, the CSD System was distributed to academics in 70 countries.

During the 1980s, interest in the CSD System from pharmaceutical and agrochemicals companies increased significantly. This led to the establishment of the Cambridge Crystallographic Data Centre (CCDC) as an independent company in 1987, with the legal status of a non-profit charitable institution, and with its operations overseen by an international board of governors. The CCDC moved into purpose-built premises on the site of the University Department of Chemistry in 1992.

Kennard retired as Director in 1997 and was succeeded by David Hartley (1997-2002) and Frank Allen (2002-2008). Colin Groom was appointed as executive director from 1 October 2008[3] to September 2017.[4] And most recently, Juergen Harter was appointed CEO in June 2018.[5]

CCDC software products diversified to the use of crystallographic data in applications in the life sciences and crystallography. Much of this software development and marketing is carried out by CCDC Software Limited (founded in 1998), a wholly owned subsidiary which covenants all of its profits back to the CCDC.

Although the CCDC is a self-administering organization, it retains close links with the University of Cambridge, and is a University Partner Institution that is qualified to train postgraduate students for higher degrees (PhD, MPhil).

The CCDC established US applications and support operations in the US in October 2013,[6][7] initially at Rutgers, the State University of New Jersey, where it is co-located with the RCSB Protein Data Bank

Contents

One Millionth Structure Added to CSD
One Millionth Structure Added to CSD, CSD ID: XOPCAJ

The CSD is updated with about 50,000 new structures each year,[8] and with improvements to existing entries. Entries (structures) in the repository are released for public access as soon as the corresponding entry has appeared in the peer-reviewed scientific literature. Meanwhile, data can also be deposited and published directly through the CSD without an accompanying scientific article as what is known as a CSD Communication.

Periodically, general statistics about the breadth of CSD holdings are reported, for example the January 2014 report.[9] Шаблон:As of, the summary statistics are as follows:[10]

Query structures % of CSD
Total # of structures Шаблон:Nts 100.0
# of different compounds Шаблон:Nts -
# of literature sources Шаблон:Nts -
Organic structures Шаблон:Nts 43.5
Transition metal present Шаблон:Nts 48.2
alkali or alkaline earth metal present Шаблон:Nts 4.8
main group metal present Шаблон:Nts 10.3
3D coordinates present Шаблон:Nts 94.6
Error-free coordinates Шаблон:Nts 98.81
Neutron studies Шаблон:Nts 0.2
Powder diffraction studies Шаблон:Nts 0.5
Low/high temp. studies Шаблон:Nts 50.8
Absolute configuration determined Шаблон:Nts 2.9
Disorder present in structure Шаблон:Nts 25.8
Polymorphic structures Шаблон:Nts 3.0
R-factor < 0.100 Шаблон:Nts 94.4
R-factor < 0.075 Шаблон:Nts 85.3
R-factor < 0.050 Шаблон:Nts 55.8
R-factor < 0.030 Шаблон:Nts 12.3
No. of atoms with 3D coordinates Шаблон:Nts -

As of January 2019, the top 25 scientific journals in terms of publication of structures in the CSD repository were:[11]

1. Шаблон:Nts structures were reported in Inorg. Chem.
2. Шаблон:Nts structures were reported in Dalton & J. Chem. Soc., Dalton Trans.
3. Шаблон:Nts structures were reported in Organometallics
4. Шаблон:Nts structures were reported in J. Am. Chem. Soc.
5. Шаблон:Nts structures were reported in Acta Crystallogr. Sect. E
6. Шаблон:Nts structures were reported in Chem. Eur. J.
7. Шаблон:Nts structures were reported in J. Organomet. Chem.
8. Шаблон:Nts structures were reported in Angew. Chem. Int. Ed.
9. Шаблон:Nts structures were reported in Inorg. Chim. Acta
10. Шаблон:Nts structures were reported in Chem. Commun. & J. Chem. Soc.
11. Шаблон:Nts structures were reported in CSD Communications
12. Шаблон:Nts structures were reported in Acta Crystallogr. Sect. C
13. Шаблон:Nts structures were reported in Polyhedron
14. Шаблон:Nts structures were reported in Eur. J. Inorg. Chem.
15. Шаблон:Nts structures were reported in J. Org. Chem.
16. Шаблон:Nts structures were reported in Cryst. Growth Des.
17. Шаблон:Nts structures were reported in CrystEngComm
18. Шаблон:Nts structures were reported in Organic Letters
19. Шаблон:Nts structures were reported in Z. Anorg. Allg. Chem.
20. Шаблон:Nts structures were reported in Acta Crystallogr. Sect. B
21. Шаблон:Nts structures were reported in Tetrahedron Шаблон:Nts structures were reported as Private Communication to the CSD
22. Шаблон:Nts structures were reported in J. Mol. Struct.
23. Шаблон:Nts structures were reported in Tetrahedron Lett.
24. Шаблон:Nts structures were reported in Eur. J. Org. Chem.
25. Шаблон:Nts structures were reported in New Journal of Chemistry

These 25 journals account for 704,541 of the 996,193 or 70.7% of the structures in the CSD.

These data show that most structures are determined by X-ray diffraction, with less than 1% of structures being determined by neutron diffraction or powder diffraction. The number of error-free coordinates were taken as a percentage of structures for which 3D coordinates are present in the CSD.

The significance of the structure factor files, mentioned above, is that, for CSD structures determined by X-ray diffraction that have a structure file, a crystallographer can verify the interpretation of the observed measurements.

Growth trend

Historically, the number of structures in the CSD has grown at an approximately exponential rate passing the 25,000 structures milestone in 1977, the 50,000 structures milestone in 1983, the 125,000 structures milestone in 1992, the 250,000 structures milestone in 2001, the 500,000 structures milestone in 2009,[12][13][14] and the 1,000,000 structures milestone on June 8, 2019.[15] The one millionth structure added to CSD is the crystal structure of 1-(7,9-diacetyl-11-methyl-6H-azepino[1,2-a]indol-6-yl)propan-2-one.

Файл:Growth Trend of Structure in CSD.svg
Growth Trend of Structure in CSD from 1965 - 2018[11]
Number of published structures per year
Year # published Total
2018 53429 Шаблон:Nts
2017 55031 Шаблон:Nts
2016 54975 Шаблон:Nts
2015 53610 Шаблон:Nts
2014 50759 Шаблон:Nts
2013 48025 Шаблон:Nts
2012 45199 Шаблон:Nts
2011 43882 Шаблон:Nts
2010 41240 Шаблон:Nts
2009 40627 Шаблон:Nts
2008 36802 Шаблон:Nts
2007 36569 Шаблон:Nts
2006 34713 Шаблон:Nts
2005 31733 Шаблон:Nts
2004 27988 Шаблон:Nts
2003 26287 Шаблон:Nts
2002 24306 Шаблон:Nts
2001 21781 Шаблон:Nts
2000 19998 Шаблон:Nts
1999 18780 Шаблон:Nts
1998 17289 Шаблон:Nts
1997 15896 Шаблон:Nts
1996 15487 Шаблон:Nts
1995 13001 Шаблон:Nts
1994 12290 Шаблон:Nts
1993 12032 Шаблон:Nts
1992 10691 Шаблон:Nts
1991 9941 Шаблон:Nts
1990 8935 Шаблон:Nts
1989 7750 Шаблон:Nts
1988 7644 Шаблон:Nts
1987 7472 Шаблон:Nts
1986 6873 Шаблон:Nts
1985 6911 Шаблон:Nts
1984 6511 Шаблон:Nts
1983 5250 Шаблон:Nts
1982 5233 Шаблон:Nts
1981 4666 Шаблон:Nts
1980 4252 Шаблон:Nts
1979 3876 Шаблон:Nts
1978 3415 Шаблон:Nts
1977 3092 Шаблон:Nts
1976 2735 Шаблон:Nts
1975 2171 Шаблон:Nts
1974 2142 Шаблон:Nts
1973 1991 Шаблон:Nts
1972 1969 Шаблон:Nts
1971 1548 Шаблон:Nts
1970 1261 Шаблон:Nts
1969 1130 Шаблон:Nts
1968 975 Шаблон:Nts
1967 936 Шаблон:Nts
1966 683 Шаблон:Nts
1965 656 Шаблон:Nts
1923-1964 4512 Шаблон:Nts

Note: data for 1923-1964 are aggregated together in the last line of the table.

File format

3D printed model of Benzoic Acid
3D printed model of Benzoic Acid, taken from a crystal structure determination, created using coordinates from the Cambridge Structural Database, and via the CCDC program Mercury. The top model shows a single molecule of benzoic acid. The bottom model shows a hydrogen-bonded dimer.

The primary file format for CSD structure deposition, adopted around 1991, is the "Crystallographic Information file" format, CIF.[16]

The deposited CSD files can be downloaded in the CIF format. The validated and curated CSD files can be exported in a wide range of formats, including CIF, MOL, Mol2, PDB, SHELX and XMol, using tools in the CSD System.

The CCDC uses two different codes to distinguish between the deposited dataset and the curated CSD entry. For example, one specific ‘CSD Communication’ of an organic molecule was deposited with the CCDC and assigned the deposition number 'CCDC-991327.' This allows free public access to the data as deposited. From the deposited data, selected information is extracted to prepare the validated and curated CSD entry which was assigned the refcode 'MITGUT'. As a part of the curation process, CCDC also applies an algorithm, DeCIFer, to help the editors assign chemistry to structures when those representations (e.g. bond types and charge assignments etc.) are missing from the original CIF files submitted.[8] The validated and curated entry is included in the CSD System and WebCSD distributions, with availability restricted to those making appropriate contributions.

Viewing the data

Файл:XURZAN.jpg
3D printed model of 1-methyl-2,3,4,5-tetrakis((trimethylsilyl)ethynyl)-1H-pyrrole structure. CSD Identifier: XURZAN

Each data set in CSD can be openly viewed and retrieved using the free Access Structure service. Through this web-browser based service, users can view the data set in 2D and 3D, obtain some basic information about the structure, and download the deposited data set. More advanced search functions and curated information are available through the subscription based CSD system.

Besides using the CSD system, the structure files may be viewed using one of several open source computer programs such as Jmol. Some other free, but not open source programs include MDL Chime, Pymol, UCSF Chimera, Rasmol, WINGX,[17] the CCDC provides a free version of its visualization program Mercury.

Starting from 2015, Mercury from CCDC also provides the functionality to generate 3D print ready file from structures in CSD.[18]

See also

References

Шаблон:Reflist

External links


Шаблон:Crystallography