[sdpd] Re: Challenging Endeavour

["Dr. Michael Berndt" <berndt... @crystalimpact.com>]

Dear All,

please accept our apologize, if anybody became confused by the word 'clone'.
Herewith we confirm, that ESPOIR and ENDEAVOUR are completely independent
developments. We changed the corresponding paragraph in our News page to
avoid further confusion.

Though the code of ENDEAVOUR is not open for good reasons (see below), the
origin and algorithms used in ENDEAVOUR are no secret. ENDEAVOUR solves
crystal structures from powder patterns by a combined global optimization of
the difference between the calculated and the measured diffraction pattern
and of the potential energy of the system ("Pareto-optimization"). You can
find details in http://www.crystalimpact.com/endeavour/background.htm. A
more detailed description was accepted by J.Appl.Cryst for publication, and
you will find a hint on our News page as soon as it is available.

Besides this, the source code of ENDEAVOUR is a complete new development; it
is written in C and is not based on any other program (e.g. RMCA). Its
development was inspired by Prof. McGreevy's remark that the RMC-method may
not be applied to the solution of crystal structures because of the many
deep local minima on the corresponding hypersurface.

Concerning Prof. LeBail's "challenge": Unfortunately, ENDEAVOUR is not able
to deal with uncharged molecules at the moment (though this will change in
the next months !). Hence, we are only able to perform calculations on the
structures of CuVO3, PbSO4 and TeI. In this sense we accept the challenge,
and we will report about the results when they are available.

Concerning 'open code': We understand and agree with you, that scientific
software of general interest should be open - at least after publication.
But this is valid only for projects which are funded by public resources.
we have to point out to the fact, that CRYSTAL IMPACT and the development
of ENDEAVOUR are NOT funded by ANY university or any other public resource.
That's why we have to sell our work and products. So it's obvious, that we
CANNOT open our code, otherwise we would have nothing to sell and could
stop working. You wouldn't ask Philips or MSI to open their code, would you?

Sincerely yours

The ENDEAVOUR team

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Dr. Michael Berndt
CRYSTAL IMPACT
K.Brandenburg & M.Berndt GbR
E-Mail: berndt... @crystalimpact.com
URL: http://www.crystalimpact.com
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