The functions and physical properties of solid materials, such as magnetic order and unconventional superconductivity, are greatly influenced by the orbital state of the outermost electrons (valence electrons) of the constituent atoms. In other words, it could be said that the minimal unit that determines a solid material’s physical properties consists of the orbitals occupied by the valence electrons. Moreover, an orbital can also be considered a minimal unit of ‘shape,’ so the orbital state in a solid can be deduced from observing the spatially anisotropic distribution of electrons (in other words, from how the electron distribution deviates from spherical symmetry).
Click here for original story, Direct observation of a single electron’s butterfly-shaped distribution in titanium oxide
Source: Phys.org