1 Introduction

1.3 Q-Chem Features

Quantum chemistry methods have proven invaluable for studying chemical and physical properties of molecules. The Q-Chem system brings together a variety of advanced computational methods and tools in an integrated ab initio software package, greatly improving the speed and accuracy of calculations being performed. In addition, Q-Chem will accommodate larger molecular structures than previously possible, with no loss in accuracy, thereby bringing the power of quantum chemistry to critical research projects for which this tool was previously unavailable. Below is a reverse-chronological listing of new features added to Q-Chem.