Effective collision strengths for fine-structure forbidden transitions among the 2s22p3 levels of Ne IV

Effective collision strengths for electron-impact excitation of the N-like ion NeIv are calculated in the close-coupling approximation using the multichannel R-matrix method. Specific attention is given to the 10 astrophysically important fine-structure forbidden transitions among the S-4(0), D-2(0) and P-2(0) levels in the 2s(2)2p(3) ground-state configuration. The expansion of the total wavefunction incorporates the lowest 11 LS eigenstates of NeIV, consisting of eight n = 2 terms with configurations 2s(2)2p(3), 2S2p(4) and 2p(5), together with three n = 3 states of configuration 2s(2)2p(2)3s. We present in graphical form the effective collision strengths obtained by thermally averaging the collision strengths over a Maxwellian distribution of velocities, for all 10 fine-structure transitions, over the range of electron temperatures log T(K) = 3.6 to lag T(K) = 6.1 (the range appropriate for astrophysical applications). Comparisons are made with the earlier, less sophisticated close-coupling calculation of Giles, and excellent agreement is found in the Limited temperature region where a comparison is possible [log T(K) = 3.7 to log T(K) = 4.3]. At higher temperatures the present data are the only reliable results currently available.