Why is the ZORA/TZ2P basis set for U.5d the same as for ZORA/TZP?
The reason for doing this is to make the TZ2P basis set complete, which may be convenient in case a user is doing everything within the same basis. In this case the TZP basis set is already of TZ2P quality. The removal of a basis function will, however, reduce the quality to below TZP. Note that for most lanthanide and actinide frozen core basis sets going from TZP to TZ2P will not give you extra basis functions.
