The Physics and Astronomy Classification Scheme® (PACS) was developed by the American Institute of Physics (AIP) and has been used in Physical Review since 1975 to identify fields and sub-fields of physics. PACS is a hierarchical partitioning of the whole spectrum of subject matter in physics, astronomy, and related sciences.
Further information is available on AIP's main PACS website. Please note that PACS is no longer being maintained; the most recent PACS scheme is from 2010 and is available at http://www.aip.org/publishing/pacs/pacs-2010-regular-edition. An alphabetical index is also available at http://www.aip.org/publishing/pacs/pacs-alphabetical-index
In 2015, APS will introduce a new classification scheme (taxonomy) for physics that will replace PACS.
Earlier versions of PACS are no longer available on this website. If you need to access previous versions, please send a message to help@aps.org.