the appropriate dipole-allowed excitation energy $\epsilon_N(q)$ is employed. For efficient representation, the excitation energies along each isoelectronic sequence are parameterized by the expression $$\begin{aligned}
\epsilon_N(q) & = & \sum_{j=0}^5 p_{N,j} \left(\frac{q}{10}\right)^j\ .
\label{eqepsilon}\end{aligned}$$ These parameters, which are determined by fitting the above expression to the available NIST excitation energies [@nist], are listed in Table \[table1\].

[lcrrrrrr]{} Li-like & 3 & 1.963\[+0\] & 2.030\[+1\] & -9.710\[-1\] & 8.545\[-1\] & 1.355\[-1\] & 2.401\[-2\]\
Be-like & 4 & 5.789\[+0\] & 3.408\[+1\] & 1.517\[+0\] & -1.212\[+0\] & 7.756\[-1\] & -4.100\[-3\]\
 N-like & 7 & 1.137\[+1\] & 3.622\[+1\] & 7.084\[+0\] & -5.168\[+0\] & 2.451\[+0\] & -1.696\[-1\]\
Na-like & 11 & 2.248\[+0\] & 2.228\[+1\] & -1.123\[+0\] & 9.027\[-1\] & -3.860\[-2\] & 1.468\[-2\]\
Mg-like & 12 & 2.745\[+0\] & 1.919\[+1\] & -5.432\[-1\] & 7.868\[-1\] & -4.249\[-2\] & 1.357\[-2\]\
 P-like & 15 & 1.428\[+0\] & 3.908\[+0\] & 7.312\[-1\] & -1.914\[+0\] & 1.051\[+0\] & -8.992\[-2\]\
H-, He-, Ne-like & 1,2,10 & $\infty^{\dag}$ & 0.0 & 0.0 & 0.0 & 0.0 & 0.0\
B-, C-, O-, F-like & 5,6,8,9 & 0.0 & 0.0 & 0.0 & 0.0 & 0.0 & 0.0\
Al-, Si-, S-, Cl-like & 13,14,16,17 & 0.0 & 0.0 & 0.0 & 0.0 & 0.0 & 0.0\
& 