Oscillator Strengths and Einstein Coefficients

From the definition of the oscillator strength f j we obtain the relation 

For atoms with p outer-shell electrons which have excitation energies within the spectral range under consideration, (2.57a) can be generalized to the 

The summation extends over all levels (including the continuum) which are accessible from level by electric dipole transitions. If is an excited level, induced emission to lower levels may occur, which diminishes the effective absorption. The corresponding oscillator strengths f. j with are therefore negative. 

This implies that the two D-lines carry 98% of the total oscillator strength. 

2) The f value of the intense line X = 3720 % in the iron spectrum which 

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A few of the oscillator strengths and Einstein coefficients that we have obtained are collected in tables fV and V, corresponding to transitions between states of different symmetry. The available FSSO values (16) have also been included, and it is apparent that, when comparison is possible, the QDO results and those by Raynor and Herschbach (16) conform quite well with each other. 

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