DASH is now open source and available in GitHub here.
In November 2021 DASH moved to become an open source solution. It is no longer licenced or supported by the CCDC.
Learn more about how and why the change was made here.
What is DASH?
The program DASH1, which has been distributed by the CCDC since the public release of version 1.0 in April 2001, is one of the most well-known and successful packages for crystal structure solution from powder diffraction data. The concepts behind DASH, as well as the initial software package, were first developed and published by Bill David, Kenneth Shankland, and Norman Shankland in 19982.
The software was then taken on by the CCDC to support, maintain and distribute, and DASH has also been the subject of a long-term, successful collaboration with the originators including many software and scientific improvements made over the years both by the CCDC and by the research groups of Bill David, Kenneth Shankland, and Norman Shankland. Recent research and improvements include the work done by Kabova, Shankland, and co-workers to illustrate the benefits of using conformational information (Mogul) to help solve structures3 and to fine-tune the parameters of the simulated annealing algorithm at the heart of DASH4.
Why was DASH moved out of the CSD software portfolio?
The functionality of DASH is now at the periphery of the CSD software portfolio, and as such we have not been able to spend much time developing its functionality in recent years. To make sure DASH continues to be available to use, and has the chance to grow and change, we are going to make it available as open source on GitHub. This will allow anybody to download and use DASH, and also contribute to developing it further.
This change will also give our team more time to focus on other developments within the CSD-Materials suite.
What does this mean for me as a user?
From December 2021, DASH will no longer be installed as part of the CSD installation.
From March 2022, older versions of DASH will stop working.
You will now need to download DASH from the CCDC Open Source GitHub project in the DASH repository here.
You do not need a CSD licence to access or use DASH, but the effectiveness of structure solution in DASH is still enhanced by CSD data (as shown by Kabova and co-workers4) if you do have an active CSD licence via the link to Mogul conformational data. The CCDC will continue to test and maintain the interface mechanism to Mogul data going forward to ensure this remains functional. You can also still visualise solved structures in Mercury using either the free version of Mercury or the CSD licensed version.
If you want to make changes or develop DASH functionality, you can contribute through GitHub.
What licence does DASH use now?
DASH is now available for free, for anyone to use and adapt under the MIT licence.
This means the code is openly accessible on GitHub where anyone can work on improving or extending the code. You can also report concerns or improvement ideas to the community within GitHub.
Learn more about this licence on the Open Source Initiative website here.
When did the change happen?
DASH became available in the CCDC Open Source GitHub project in November 2021.
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- DASH: a program for Crystal Structure Determination from Powder Diffraction Data. W. I. F. David, K Shankland, J. van de Streek, E. Pidcock, W. D. S. Motherwell, J. C. Cole. J. Appl. Cryst., 39, 910-915, 2006. DOI: 10.1107/S0021889806042117
- Routine Determination of Molecular Crystal Structures from Powder Diffraction Data. W. I. F. David, K. Shankland, N. Shankland, Chem. Commun., 931-932, 1998. DOI: 10.1039/a800855h
Improved crystal structure solution from powder diffraction data by the use of conformational information. E. A. Kabova, J. C. Cole, O. Korb, A. C. Williams, K. Shankland, J. Appl. Crystallogr., 2017, 50 1421-1427. DOI: 10.1107/S1600576717012596
Improved performance of crystal structure solution from powder diffraction data through parameter tuning of a simulated annealing algorithm. E. A. Kabova, J. C. Cole, O. Korb, M. Lopez-Ibanez, A. C. Williams, K. Shankland, J. Appl. Crystallogr., 2017, 50 1411-1420. DOI: 10.1107/S1600576717012602