atom 4dTable of equations for the 4d orbitals. There are five real 4d orbitals. The radial equations for all the 4d orbitals are the same.4d atomic orbitals. There are five 4d orbitals. These are labelled 4d xy, 4d xz, 4d yz, 4d x 2-y 2 and 4d z 2. The 4d z 2 name is an abbreviation for 3d (3z 2 –r