Brus equation emission energy Δ"E" = "hc"/λ, where c is the speed of light). This is useful for calculating the radius of a quantum dot from experimentally determined parameters. The overall equation is "E", "m"*, and "m"* are unique for each nanocrystal composition. For example, with CdSe nanocrystals: Brus equation The Brus equation can be used to describe the emission energy of quantum dot semiconductor nanocrystals (such as CdSe nanocrystals) in terms of the band gap energy "E", Planck's constant "h", the radius of the quantum dot "r", as well as the effective mass of the excited electron "m"* and of the
Darwin–Radau equation Darwin–Radau equation In astrophysics, the Darwin–Radau equation gives an approximate relation between the moment of inertia factor of a planetary body and its rotational speed and shape. The moment of inertia factor is directly related to the largest principal moment of inertia, "C". It is assumed that the rotating body is in hydrostatic equilibrium and is an ellipsoid of revolution. The Darwin–Radau equation states where "M" and "R" represent the mass and mean equatorial radius of the body. Here λ is the d'Alembert parameter and the Radau parameter η is defined as where "q" is the geodynamical constant and ε