forbidden transition


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forbidden transition

[fər¦bid·ən tran′zish·ən]
(quantum mechanics)
A transition between two states of a quantum-mechnical system which is considerably less probable than a competing allowed transition.
References in periodicals archive ?
18 represents a forbidden transition. Line Wavelength Transition no.
The values of n are equal to 1/2 and 3/2 for direct allowed and forbidden transitions, respectively.
This instrument enables classroom demonstrations of simple topics, such as free radicals in everyday life, to far less intuitive subjects like electron density, spin-orbit coupling, spin-spin exchange and forbidden transitions. Bruker Corp.
m = 1/2 and 3/2 corresponds to direct allowed and direct forbidden transitions and m = 2, 3 corresponds to indirect allowed and indirect forbidden transitions, respectively [22].
For direct allowed transitions, m = 1/2, for the direct forbidden transitions, m = 3/2, while m = 2 and m = 3 correspond to indirect allowed and forbidden transitions.
The forbidden transitions (M1 and E2) between the 2[s.sup.2]2p-2[s.sup.2]2p and [2s2p.sup.2]-[2sp.sup.2] levels become possible through the fine-structure splitting of LS term into a series of J levels.