The Atomic Simulation Environment (ASE) tool collection suite was designed as a flexible, easy-to-use, and customizable approach for the manipulation of quantum chemical models as well as for setting up and running the calculations required and for the analysis of the final results.
The development of ASE was originally started at the Technical University of Denmark but received also significant contributions from a large, international community. While ASE is available under a GNU LGPL license, a modified version of this library is shipped together with the Amsterdam Modeling Suite.
External ASE links:
ASE Download as an external library (mind to set the correct Python environment variables)
On Windows machines the developers of the ASE library provide only a partial support, see the ASE website for further details.