Explore: Forbidden Transitions

In spectroscopy, a forbidden mechanism (forbidden transition or forbidden line) is a spectral line associated with absorption or emission of photons by

centrosymmetric environment, transitions between like atomic orbitals such as s–s, p–p, d–d, or f–f, transitions are forbidden. The Laporte rule (law) applies

beta-particle energy. It is a straight line for allowed transitions and some forbidden transitions, in accord with the Fermi beta-decay theory. The energy-axis

u_{n}} and v m {\displaystyle v_{m}} vanishes, the associated transition is "forbidden" (or, rather, much less likely than in cases where it is closer

of the transition:,, r = 1/2 for direct allowed transitions r = 3/2 for direct forbidden transitions. r = 2 for indirect allowed transitions r = 3 for

their source as doubly ionized oxygen. Other transitions include the forbidden 88.4 μm and 51.8 μm transitions in the far infrared region. Permitted lines

lines, it was called nebulium. Bowen was able to calculate the forbidden transitions of doubly ionized oxygen to be exactly where the lines had been

excited electrons may make "forbidden" transitions. The spectral lines associated with such transitions are known as forbidden lines. The energy and momentum

gap and the electronic transition must undergo momentum transfer to satisfy conservation. Such indirect "forbidden" transitions still occur, however at

(typically less than a few thousand particles per cm³) for forbidden transitions. For allowed transitions, the gas density can be substantially higher. At higher