The development of emerging technologies such as molecular computing, nanotechnology, and next generation catalysts will continue to place increasing demands on chemical simulation software, requiring more capabilities and more sophisticated simulation environments.  Such software will be too complex for a single group, or even a single discipline to develop independently.  Coupling multiple physical models in one domain and coupling simulations across multiple time and length-scales will become the norm rather than the exception. These simulations will also run on more complicated and diverse hardware platforms, potentially with hundreds of thousands of processors and performance exceeding one petaFLOP/s.  This evolution will transform the way chemists must think about scientific problems, models and algorithms, software lifecycle and the use of computational resources.  Advances in chemical science critical to DOE and national challenges require adoption of new approaches for large-scale collaborative development and a flexible, community-based architecture. We propose to employ the infrastructure of the Common Component Architecture to develop interfaces among three of the most important computational chemistry codes in the world: General Atomic and Molecular Electronic Structure System (GAMESS), the Massively Parallel Quantum Chemistry program (MPQC) and Northwest Chem (NWChem).