Program Package for ab initio Electronic Structure Calculations. TURBOMOLE is a quantum chemical program package, initially developed in the group of Prof. Dr. Reinhart Ahlrichs at the University of Karlsruhe and at the Forschungszentrum Karlsruhe. All researchers interested in TURBOMOLE development can submit project proposals to the company. The proposals are reviewed by the founding members of TURBOMOLE GmbH. Upon acceptance of the project a cooperation agreement is made between the TURBOMOLE GmbH and the research institution of the developer and, subsequently, access to the TURBOMOLE code is granted. With almost 20 years of continuous development TURBOMOLE has become a valuable tool used by academic and industrial researchers. It is used in research areas ranging form homogeneous and heterogeneous catalysis, inorganic and organic chemistry to various types of spectroscopy, and biochemistry. The philosophy behind the development of the code was, and still is, its usefulness for applications.Presently TURBOMOLE is one of the fastest and most stable codes available for standard quantum chemical applications. Unlike many other programs, the main focus in the development of TURBOMOLE has not been to implement all new methods and functionals, but to provide a fast and stable code which is able to treat molecules of industrial relevance at reasonable time and memory requirements.