  A number of new functionalities have been added to the Alloy Theoretic
Automated Toolkit (ATAT) since it was last reviewed in this journal in 2002.
ATAT can now handle multicomponent multisublattice alloy systems,
nonconfigurational sources of entropy (e.g. vibrational and electronic
entropy), Special Quasirandom Structures (SQS) generation, tensorial cluster
expansion construction and includes interfaces for multiple atomistic or ab
initio codes. This paper presents an overview of these features geared towards
the practical use of the code. The extensions to the cluster expansion
formalism needed to cover multicomponent multisublattice alloys are also
formally demonstrated.
