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tokens: et al. ( 1989 ) code using a model of 14 configurations, our grasp 1 levels in the excited configurations lie closer to the NIST ones. In the case of four energy levels ( 2 D 5/2,3/2 , 4 P 5/2,3/2 ), our calculated energy levels are more closer to NIST than those of Aggarrwal et al. ( 2003 ). The average percentage difference of these grasp energies with NIST values is 2.2 per cent, and the maximum error of 6.3 per cent appears for the first excited state ( 2 D 3/2 ) of ground configuration. For more accurate target states we adopt a model of 13 electronic configurations which yields target-states energies as closer to NIST values as possible. For instance, our calculated energy levels 2 D 3/2,5/2 associated with the configuration 3s3p 4 lie more closer to the observed values as compared to existing calculations. The remaining set of energy levels are almost of the same accuracy as those of previous data when compared to experimental energies. From this comparison it is evident that present grasp 1 calculated N -electron target wavefunctions demonstrate good agreement with experimental values, which is necessary for more accurate PI cross-sections of Ni xiii . In order to further ascertain the accuracy of target wavefunctions, we have compared weighted oscillator strength ( gf -values) of electric dipole (E1) transitions of Ni xiv where available (Fritzsche et al. 1998 ; Landi Bhatia 2010 ) in the literature. In Table 2 , we present our calculated gf -values of E1 transitions in length form only from the ground state and first exited states to the 41 excited levels of Ni xiv ion. The online version of Table 2 contain the gf -values of all dipole transitions among the 41 fine-structure levels. The indices of lower and upper levels of a transition used in Table 2 are defined in Table 1 . The agreement between our calculated oscillator strengths and grasp 92 calculations (Fritzsche et al. 1998 ) is within 15 per cent for majority of the strong dipole transitions with gf -values ≥ 0.01, while fac oscillator strengths (Landi Bhatia 2010 ) lie within 25 per cent with the exception of few transitions for instance ( 2 D 3/2 – 2 P 3/2 ). We note some significant differences with those of Fritzsche et al. ( 1998 ) and Landi Bhatia 2010 within 70 per cent for weaker transitions like in the case of 4 S 3/2 – 4 F 5/2 and 2 D 3/2 – 2 S 1/2 transitions. Apart from these differences, the overall agreement between present MCDF and previous MCDF (Fritzsche et al. 1998 ) oscillator strengths is quite good. This gives confidence in the accuracy of target states to calculate PI cross-sections. Table 2. Comparison of present weighted oscillator strengths ( gf -values, dimensionless) for E1 transitions in Ni xiv with other theoretical calculations. The complete table is available online only. Notes. a fac : Oscillator strengths from fac code (Landi Bhatia 2010 ). b grasp 92: Oscillator strengths from grasp 92 code (Fritzsche et al. 1998 ). Figs 1 – 3 display our