Annual Reports in Computational Chemistry (ARCC) focuses on providing timely reviews of topics important to researchers in the field of computational chemistry. The ARCC is published and distributed by Elsevier and is sponsored by the Division of Computers in Chemistry (COMP) of the American Chemical Society. Members in good standing of the COMP Division receive a copy of the ARCC as part of their membership benefits. The ARCC is assembled entirely by volunteers in order to produce a high-quality scientific publication at the lowest possible cost. The Editors extend their gratitude to the many people who have given their time to make this publication possible. We hope that you find the ARCC to be interesting and valuable. We are actively planning future volumes and are soliciting input from our readers about future topics. Please contact either of us with your suggestions and/or to volunteer to be a contributor.