The ADF program uses Slater-Type Orbitals.
There are a number of basis sets that can be freely downloaded
from this site.
These basis sets are optimized for the use in the zeroth-order regular approximated (ZORA) relativistic equation, which is an excellent approximation to the fully relativistic Dirac equation, especially in the valence region, which is important in quantum chemical calculations.
|DZ fc:||Double zeta frozen core|
|DZ ae:||Double zeta all electron|
|TZP fc:||Triple zeta frozen core 1 polarization function|
|TZP ae:||Triple zeta all electron 1 polarization function|
|TZ2P fc:||Triple zeta frozen core 2 polarization functions|
|TZ2P ae:||Triple zeta all electron 2 polarization functions|
|QZ4P ae:||Quadruple zeta all electron 4 polarization functions|
E. van Lenthe and E.J. Baerends, Optimized Slater-type basis sets for the elements 1-118. Journal of Computational Chemistry 24, 1142 (2003)
Especially for the lighter elements more STO basis sets are available in the data bases of the ADF program. One of the main developments in this respect are the even tempered basis sets developed by Del Chong.