Final answer:
To find standard data sources for d orbital energies, one should refer to physical chemistry journals, standards databases, or quantum chemistry textbooks. These energies, derived from Photoelectron Spectroscopy, are subject to electron-electron interactions and are complex for multi-electron systems beyond hydrogen. Such data aid in understanding chemical properties and atomic structures.
Step-by-step explanation:
Orbital Energies and Atomic Structure
To locate a standard data source for the energy levels of d orbitals and other atomic orbitals obtained via Photoelectron Spectroscopy, authoritative references like journal articles in the field of physical chemistry or atomic physics, databases from national standards organizations, or textbooks on quantum chemistry and spectroscopy would be highly recommended. Photoelectron Spectroscopy is an experimental technique that measures the energies required to ionize electrons from atoms, providing detailed insights into the electronic structure of atoms. The measured energy of an electron in a particular orbital reflects its binding energy to the nucleus.
For hydrogen and other single-electron systems, the orbital energy is dependent solely on the principal quantum number n, with all orbitals having the same n being degenerate (having the same energy). However, for multi-electron atoms, interactions such as electron-electron repulsion and shielding effects result in subshells with different l values having different energies. This means that within a shell, orbital energies typically increase in the order of s < p < d < f, although overlaps like the 3d being higher in energy than the 4s are observed for larger atoms.