Q-Chem is equipped with many standard basis sets,11, B. P. Pritchard, D. Altarawy, B. Didier, T. D. Gibson, and T. L. Windus (2019) and allows the user to specify the required basis set by its standard symbolic representation. The available built-in basis sets include the following types:
Dunning basis sets293
Correlation-consistent (cc) Dunning basis sets, including:
Versions with core–valence polarization functions,924 cc-pCVXZ and cc-pwCVXZ (X = D, T, Q)
Partially-augmented core–valence polarization basis sets jun-, jul-, and aug-cc-pCVXZ (X = D, T, Q)
Ahlrichs basis sets993
Universal Gaussian basis set (UGBS)256
In addition, Q-Chem supports the following features:
Extra diffuse functions available for high quality excited-state calculations.
Standard polarization functions.
, , , , , and angular momentum types of basis functions (for energy calculations, up to are supported).
Pure and Cartesian basis functions.
Mixed basis sets (see Section 8.5).
Basis set superposition error (BSSE) corrections.
Automatic, on-the-fly generation of a superposition of atomic densities (SAD) guess for any basis set (including general and mixed basis sets) and any SCF level of theory (see Section 4.4.2).
The following $rem keyword controls the basis set: