If you want to use the CAABA/MECCA chemistry model, we ask that you
contact us first at rolf.sander@mpic.de and let us know what your
research plans are. You are welcome to use CAABA/MECCA under the terms
described here. Since we want CAABA/MECCA to be useful for the whole
scientific community, we decided to make the source code available under
the GNU General Public License (GPL). Basically, the GPL allows you to
use CAABA/MECCA at no charge. However, the GPL was not written with
scientific programs in mind. Therefore, when you are going to publish
results based on CAABA/MECCA in a scientific journal, the Creative
Commons Attribution-NonCommerical-ShareAlike Licence also applies. In
particular, we ask you to obey these points:

    * Please discuss a potential co-authorship with us. Usually, we
      request co-authorship only, if model results obtained with
      CAABA/MECCA are the main topic of your manuscript and not, if they
      are just a minor aspect of it.

    * Please cite the following publication:
      R. Sander, A. Kerkweg, P. Jöckel & J. Lelieveld. Technical Note:
      The new comprehensive atmospheric chemistry module CAABA/MECCA.
      Atmos. Chem. Phys., 5, 445-450 (2005).

    * Please send a reprint of your paper to rolf.sander@mpic.de. We'd
      also appreciate receiving a preprint before you submit your
      manuscript.

    * If you have written additional code which is based on CAABA/MECCA,
      you must also make it available to the scientific community using
      this license. Please email us a copy of your new code. This will
      help us to coordinate developments of different research groups. 
