This is Version 1.5.1 of the package AtlasRep written for GAP 4, whose aim is to provide an interface between GAP and the Atlas of Group Representations, a database that comprises representations of many almost simple groups and information about their maximal subgroups. This database is available independent of GAP.

The AtlasRep package consists of this database and a GAP interface. The latter allows the user to get an overview of the database, and to access the data in GAP format.

There is a manual (available in HTML and pdf format) that describes the available functions in detail.

Up to now, the package has been developed and tested on Linux, it may or may not work on other platforms.

The package requires GAP 4.5 (or a newer version of GAP).


An overview of new features in this version can be found in Section "What's New in AtlasRep" of the package manual.

The bibliographies in the Atlas of Finite Groups and in the Atlas of Brauer Characters are available online, see here.

The following information will be updated regularly, also before the next release of the package.

For updating the table of contents of the server data, one can copy the file atlasprm.g to the directory pkg/atlasrep/gap of the GAP installation.

An overview of the Atlas data currently available via the GAP interface can be found here.

A list of changes of server data describes which files have been changed in the meantime. It is thought mainly for documenting bugfixes in that part of the ATLAS of Group Representations that can be accessed via the GAP interface.


The data files of the ATLAS of Group Representations have been prepared by Robert Wilson, Peter Walsh, Jonathan Tripp, Ibrahim Suleiman, Richard Parker, Simon Norton, Simon Nickerson, Steve Linton, John Bray, and Rachel Abbott (in reverse alphabetical order).

The GAP interface was written by Thomas Breuer and Simon Nickerson.


If you have used the AtlasRep package to solve a problem then please send a short email to Robert Wilson or Thomas Breuer about it.

Any comments about the package are very welcome. If you have found important features missing or if there is a bug, let us know and we will try to address it in the next version of the package. Messages concerning the data of the package should be sent to Robert Wilson, messages concerning the GAP interface to Thomas Breuer.


If you want to get Version 1.5.1 of the AtlasRep package then download the gzipped tar archive (ca. 1260k). Further information is contained in the README file.

(The README file and the archives are available also on the GAP servers.)

Note that the package archives do NOT contain the database part of the package; the GAP interface accesses the data on demand via the internet.

Here is a starter archive in gzipped tar format (ca. 22M) containing many small representations and programs. (Copy it into the pkg directory of the GAP installation, and unpack it there.)

The current table of contents of the server data is contained in the file atlasprm.g (ca. 640k). The recommended way to download this file is described in the manual section "Maintaining the Local Data of the AtlasRep Package".

Up to version 1.5.0 of the package, the data format of the table of contents file was different. The old format is available at OLD/atlasprm.g (ca. 500k).

For those who cannot use the GAP package IO and therefore want to use wget instead: For Windows users, wget seems to be not available in a standard operating system. See WGET for Windows for information about wget for Windows (and executables).

Related Links

[Atlas Home] [GAP Home] [Atlas Bibliographies]

File created on 11-Nov-2000 by Thomas Breuer.
Last modified on 27-Mar-2016 by Thomas Breuer.