Aten is a molecular modelling package that allows editing and manipulation of atoms and molecules in isolated and periodic systems, and will be of use to anyone interested in molecular simulation - e.g. molecular dynamics, ab initio simulations etc. Aten offers full editing via either graphical user interface or command line (scripted) operation. Aten is completely free, and available for Mac, Windows, and Linux systems.
Aten is designed primarily for those wishing to create input coordinates for molecular dynamics packages (e.g. the CCP5 code DL_POLY), but is equally well suited to load and edit crystal structures and single molecules in isolation. Aten can assign atom types from common forcefields based on connectivity through its typing language NETA, and thus write out the complete forcefield expression for a system, including both inter- and intra-molecular terms, provided a suitable source forcefield file is available.
Support for different file formats is made through Aten's plugin system (since v2.0, superseding the old filters system), and offers out-of-the-box handling for many common (and not-so-common) file formats. These range from simple xyz and mol2 formats, through to crystallographic information format (cif) files, CONFIG and FIELD inputs for DL_POLY, common formats for the RMCProfile and EPSR codes, and input files for Mopac and GAMESS-US. Need a different format? Add a plugin! Plugins also provide additional functionality to the code, such as the (in-progress) OpenMOPAC plugin.
Build systems atom-by-atom, fragment-by-fragment, or perform scripted building operations using Aten's powerful command language.
Visualise gridded, volumetric or 2D surface data along with coordinate data. For instance, visualise spatial density functions, molecular orbitals, height maps etc.
The Disorder builder in Aten allows random configurations of a certain number / density of molecules to be generated, optionally confining them to specific regions.
Automatically create energy expressions for models from predefined forcefields using Aten's typing language NETA.
Export models and forcefield expressions in a variety of formats, develop support for your code of choice with a plugin, and save high-quality images and (via external encoders) films.