All basis sets in the ZORA directory have been built and tested by Erik van Lenthe, who also tested and improved many basis sets in the directories SZ-TZ2P (I-V) . Del Chong inspired the present efforts and provided his completeness profile utilities. Furthermore he devised and tested the ET basis sets on atomic energies and suggested how many polarization functions should be chosen for each element and how to choose their exponents properly. Stan van Gisbergen generated the basis set utility scripts and did some molecular tests on the ET basis sets. He also performed molecular tests to define new exponents for some ADF polarization functions. Pieter Vernooijs has performed much of the earlier work on basis and fit set generation in ADF. Evert-Jan Baerends provided much useful general advice on the proper construction of balanced basis sets.