The collision strength of the [Ne v] infrared fine-structure lines

The calculation of accurate collision strengths for atomic transitions has been a long standing problem in quantitative spectroscopy. Most modern calc ulations are based on the R-matrix method and problems pertaining to the us e of this method have led to a discussion of the accuracy of these results. More in particular, based on an analysis of the spectra of NGC 3918 and NG C 6302, Clegg et al. (1987) and Oliva et al. (1996) have questioned R-matri x calculations for the infrared [Ne V] fine-structure transitions. Using im proved flux measurements for the [Ne V] lines, we show that the conclusion that these collision strengths would be too high, is not correct. The discr epancies found by Clegg et al. (1987) can be explained by the inaccuracy of the [Ne V] 342.6 nm flux they adopted. The discrepancies found by Oliva et al. (1996) can be explained by the inaccuracy of the LRS flux for the [Ne V] 14.32 mu m line. Based on the data presented in this paper there is no r eason to assume that there are any problems with the R-matrix calculations for Ne4+ of Lennon & Burke (1994). We show that the data are accurate at th e 30 % level or better. This confirms the validity of the close coupling me thod.