利用GTOs(Gaussian Type Orbitals)来模拟STOs(SlaterType Orbitals)，根据使用GTOs的数量不同，产生了STO-3G，STO-6G。
Minimal Basis Sets
A basis set that describes only the most basic aspects of the orbitals
Extended Basis Sets
A basis set that describes the orbitals in great detail
CGTF 基组 by Dunnings
Dunning and co-workers have developed the CGTF basis sets cc-pVDZ, ccpVTZ, cc-pVQZ, and cc-pV5Z (collectively denoted cc-pVXZ), designed for use in calculation methods (such as CI) that include electron correlation. Here, ce-pVDZ stands for correlation consistent, polarized valence double-zeta. For first-row atoms. The cc-pVDZ set is [3s2p1d] and the cc-pVTZ set is [4s3p2d1f].The addition of certain primitive Gaussians to the cc-pVXZ sets gives the cc-pCVDZ, cc-pCVTZ, … sets (where CV stands for core/valence), which are designed for calculations that include correlation effects involving the core electrons. The addition of diffuse nonpolarizationand polarization functions to these sets gives the augmented sets aug-cc-pVDZ, aug-cc-pVTZ,…and aug-cc-pCVDZ, aug-cc-pCVTZ,…,suitable for correlation calculations on anions and hydrogen-bonded species.