ADDA is a C software package to calculate scattering and absorption of electromagnetic waves by particles of arbitrary geometry using the discrete dipole approximation (DDA). Its main feature is the ability to run on a multiprocessor system or multicore processors (parallelizing a single DDA simulation). ADDA is intended to be a versatile tool, suitable for a wide variety of applications ranging from interstellar dust and atmospheric aerosols to metallic nanoparticles and biological cells. Its applicability is limited only by available computer resources. As provided, ADDA should be usable for many applications without modification, but the program is written in a modular form, so that modifications, if required, should be fairly straightforward.

ADDA originated at the University of Amsterdam but has then evolved into an open-source international project. Links on the top and to the left of this page describe possible further actions. We recommend to start with a short introduction or take a look at the manual. If you choose to use ADDA, please subscribe to announcement mailing list; "registered" users of ADDA will be notified when updates to the code are made.

If you publish results obtained using ADDA, you should acknowledge the source of the code. The general reference is - M. A. Yurkin and A. G. Hoekstra, “The discrete-dipole-approximation code ADDA: capabilities and known limitations,” J. Quant. Spectrosc. Radiat. 112, 2234-2247 (2011). One may also look at a list of more specific references.

We encourage users to provide feedback in any possible way. If you have any questions, please write to the discussion group. If you have any suggestions or a bug report, submit it directly to the issue tracker, taking advantage of the open development process. Please also provide feedback on the existing issues - you may star issues that you find important (Google account is required) and/or provide some meaningful comments.

Finally, we maintain a list of publications that use ADDA. Please let us know of any papers that should be included in this list. If you are doing very large simulations with ADDA, consider them to be included in the corresponding wiki page. There is also a list of ADDA awards.