Q-Chem is a comprehensive ab initio quantum chemistry package. Its capabilities range from the highest performance DFT/HF calculations to high level post-HF correlation methods. Q-Chem tackles a wide range of problems in commercial, academic and government laboratories, including: 
1. Molecular Structures;
2. Chemical Reactions;
3. Molecular Vibrations;
4. Electronic Spectra;
5. NMR Spectra;
6. Solvation Effects.

Q-Chem provides users with some distinct advantages:
1. Fast DFT calculations with accurate linear scaling algorithms;
2. A wide range of post-HF correlation methods that are efficient and unique;
3. Quantum calculations extended with QM/MM and molecular dynamics;
4. Detailed description in Q-Chem paper.