\begin{table}%t3
\caption{\label{Tab:K:Ca:tar-str}The lowest $\Delta n_{{\rm c}} = 0, 1$ core excitation thresholds (in Rydbergs) for \ion{K}{ii} and \ion{Ca}{iii}.}
\par
%\centering
\par
\begin{tabular}{r l l l r r c l l r r r}  % 12 columns
\hline
\hline \noalign{\smallskip}
%\multicolumn{12}{c}{\vspace*{-2mm}} \\
   &         & \multicolumn{4}{c}{${\rm K}^{+}$} &   &   & \multicolumn{4}{c}{${\rm Ca}^{2+}$} \\
%\multicolumn{12}{c}{\vspace*{-2mm}} \\
%\cline{3-6}\cline{9-12}
%\multicolumn{12}{c}{\vspace*{-2mm}} \\
K  & Config. & Level(mix) & Present\tablefootmark{a} & NIST\tablefootmark{b} & MCHF\tablefootmark{c} &
K  & Config. & Level(mix) & Present\tablefootmark{a} & NIST\tablefootmark{d} & MCHF\tablefootmark{c} \\
\hline
\multicolumn{12}{c}{\vspace*{-2mm}} \\
%K   Configuration               Level                                                   Present      NIST           MCHF
 1 & $\rm 3s^{2}3p^{6}  $ & $\rm {}^{1}\hspace*{-.5mm}S_{0}~(96.3\%)$                       & $0.000000$ & $0.000000$ & $0.000000$ &
 1 & $\rm 3s^{2}3p^{6}  $ & $\rm {}^{1}\hspace*{-.5mm}S_{0}~(99.0\%)$                       & $0.000000$ & $0.000000$ & $0.000000$ \\
%\multicolumn{12}{c}{\vspace*{-2mm}} \\
 2 & $\rm 3s^{2}3p^{5}4s$ & $\rm {}^{3}\hspace*{-.5mm}P_{2}^{{\rm o}}~(93.2\%)$             & $1.480381$ & $1.480834$ & $1.400644$ &
 2 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}P_{0}^{{\rm o}}~(95.7\%)$             & $1.879530$ & $1.853273$ & $1.760169$ \\
 3 & $\rm 3s^{2}3p^{5}4s$ & $\rm {}^{3}\hspace*{-.5mm}P_{1}^{{\rm o}}~(59.7\%)$             & $1.487826$ & $1.487481$ & $1.408491$ &
 3 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}P_{1}^{{\rm o}}~(95.6\%)$             & $1.884279$ & $1.857636$ & $1.764514$ \\
 4 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}P_{0}^{{\rm o}}~(70.9\%)$             & $1.490116$ & $1.489303$ & $1.431384$ &
 4 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}P_{2}^{{\rm o}}~(95.2\%)$             & $1.893907$ & $1.866664$ & $1.773134$ \\
%\multicolumn{12}{c}{\vspace*{-2mm}} \\
 5 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}P_{1}^{{\rm o}}~(59.5\%)$             & $1.499706$ & $1.498961$ & $1.430119$ &
 5 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}F_{4}^{{\rm o}}~(95.1\%)$             & $1.952880$ & $1.934711$ & $1.844004$ \\
 6 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}P_{2}^{{\rm o}}~(81.1\%)$             & $1.505571$ & $1.502934$ & $1.436726$ &
 6 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}F_{3}^{{\rm o}}~(93.9\%)$             & $1.963210$ & $1.944456$ & $1.853118$ \\
 7 & $\rm 3s^{2}3p^{5}4s$ & $\rm {}^{3}\hspace*{-.5mm}P_{0}^{{\rm o}}~(82.4\%)$             & $1.506735$ & $1.504916$ & $1.414847$ &
 7 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}F_{2}^{{\rm o}}~(94.0\%)$             & $1.972601$ & $1.953156$ & $1.861216$ \\
%\multicolumn{12}{c}{\vspace*{-2mm}} \\
 8 & $\rm 3s^{2}3p^{5}4s$ & $\rm {}^{1}\hspace*{-.5mm}P_{1}^{{\rm o}}~(74.8\%)$             & $1.517409$ & $1.516872$ & $1.437439$ &
 8 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{1}\hspace*{-.5mm}D_{2}^{{\rm o}}~(58.9\%)$             & $2.086507$ & $2.057880$ & $1.972081$ \\
%\multicolumn{12}{c}{\vspace*{-2mm}} \\
 9 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}F_{4}^{{\rm o}}~(82.4\%)$             & $1.547896$ & $1.549602$ & $1.480702$ &
 9 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}D_{3}^{{\rm o}}~(53.7\%)$             & $2.080602$ & $2.062503$ & $1.976286$ \\
10 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}F_{3}^{{\rm o}}~(81.1\%)$             & $1.555741$ & $1.556728$ & $1.488382$ &
10 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}D_{1}^{{\rm o}}~(92.9\%)$             & $2.093231$ & $2.072514$ & $1.985320$ \\
11 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}F_{2}^{{\rm o}}~(81.3\%)$             & $1.562998$ & $1.563029$ & $1.494070$ &
11 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}D_{2}^{{\rm o}}~(54.0\%)$             & $2.095232$ & $2.072117$ & $1.984866$ \\
%\multicolumn{12}{c}{\vspace*{-2mm}} \\
12 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}D_{3}^{{\rm o}}~(35.7\%)$             & $1.633040$ & $1.634775$ & $1.561671$ &
12 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{1}\hspace*{-.5mm}F_{3}^{{\rm o}}~(57.8\%)$             & $2.081461$ & $2.097941$ & $1.995780$ \\
%\multicolumn{12}{c}{\vspace*{-2mm}} \\
13 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{1}\hspace*{-.5mm}D_{2}^{{\rm o}}~(41.6\%)$             & $1.639503$ & $1.634350$ & $1.560836$ &
13 & $\rm 3s^{2}3p^{5}4s$ & $\rm {}^{3}\hspace*{-.5mm}P_{2}^{{\rm o}}~(99.4\%)$             & $2.313063$ & $2.210253$ & $2.114045$ \\
%\multicolumn{12}{c}{\vspace*{-2mm}} \\
14 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}D_{1}^{{\rm o}}~(71.5\%)$                       & $1.644348$ & $1.644371$ & $1.570061$ &
14 & $\rm 3s^{2}3p^{5}4s$ & $\rm {}^{3}\hspace*{-.5mm}P_{1}^{{\rm o}}~(88.0\%)$                       & $2.327118$ & $2.222858$ & $2.126335$ \\
15 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{3}\hspace*{-.5mm}D_{2}^{{\rm o}}~(41.9\%)$                       & $1.645874$ & $1.643859$ & $1.569134$ &
15 & $\rm 3s^{2}3p^{5}4s$ & $\rm {}^{3}\hspace*{-.5mm}P_{0}^{{\rm o}}~(99.4\%)$                       & $2.341390$ & $2.238180$ & $2.140287$ \\
16 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{1}\hspace*{-.5mm}F_{3}^{{\rm o}}~(34.1\%)$                       & $1.645999$ & $1.645919$ & $1.571404$ &
16 & $\rm 3s^{2}3p^{5}4s$ & $\rm {}^{1}\hspace*{-.5mm}P_{1}^{{\rm o}}~(87.6\%)$                       & $2.369020$ & $2.257176$ & $2.160581$ \\
%\multicolumn{12}{c}{\vspace*{-2mm}} \\
17 & $\rm 3s^{2}3p^{5}4p$ & $\rm {}^{3}\hspace*{-.5mm}S_{1}~(97.7\%)$                                    & $1.663215$ & $1.669479$ & $1.591351$ &
17 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{1}\hspace*{-.5mm}P_{1}^{{\rm o}}~(63.1\%)$\tablefootmark{\bigstar}         & $2.545658$ & $2.545658$ & $2.492690$ \\
%\multicolumn{12}{c}{\vspace*{-2mm}} \\
18 & $\rm 3s^{2}3p^{5}4p$ & $\rm {}^{3}\hspace*{-.5mm}D_{3}~(99.9\%)$            & $1.693675$ & $1.698454$ & $1.618318$ &
   &                  &                                                &         &         &             \\
19 & $\rm 3s^{2}3p^{5}4p$ & $\rm {}^{3}\hspace*{-.5mm}D_{2}~(75.5\%)$            & $1.697258$ & $1.701166$ & $1.621064$ &
   &                  &                                                &         &         &             \\
20 & $\rm 3s^{2}3p^{5}4p$ & $\rm {}^{3}\hspace*{-.5mm}D_{1}~(76.3\%)$            & $1.705934$ & $1.708872$ & $1.628229$ &
   &                  &                                                &         &         &             \\
21 & $\rm 3s^{2}3p^{5}4p$ & $\rm {}^{1}\hspace*{-.5mm}D_{2}~(51.0\%)$            & $1.712827$ & $1.714552$ & $1.633790$ &
   &                  &                                                &         &         &             \\
22 & $\rm 3s^{2}3p^{5}4p$ & $\rm {}^{1}\hspace*{-.5mm}P_{1}~(52.5\%)$            & $1.724516$ & $1.724477$ & $1.643195$ &
   &                  &                                                &         &         &             \\
23 & $\rm 3s^{2}3p^{5}4p$ & $\rm {}^{3}\hspace*{-.5mm}P_{2}~(55.9\%)$            & $1.727938$ & $1.728285$ & $1.646621$ &
   &                  &                                                &         &         &             \\
24 & $\rm 3s^{2}3p^{5}4p$ & $\rm {}^{3}\hspace*{-.5mm}P_{0}~(99.5\%)$            & $1.730260$ & $1.729293$ & $1.648054$ &
   &                  &                                                &         &         &             \\
25 & $\rm 3s^{2}3p^{5}4p$ & $\rm {}^{3}\hspace*{-.5mm}P_{1}~(65.5\%)$            & $1.733330$ & $1.732598$ & $1.650821$ &
   &                  &                                                &         &         &             \\
26 & $\rm 3s^{2}3p^{5}4p$ & $\rm {}^{1}\hspace*{-.5mm}S_{0}~(95.2\%)$            & $1.829238$ & $1.774895$ & $1.702454$ &
   &                  &                                                &         &         &             \\
27 & $\rm 3s^{2}3p^{5}3d$ & $\rm {}^{1}\hspace*{-.5mm}P_{1}^{{\rm o}}~(90.5\%)$\tablefootmark{\bigstar}& $1.840715$ & $1.840373$ & $1.817999$ &
   &                  &                                                          &         &         &   \\
   & $\rm 3s^{2}3p^{5}4d$ & $\rm {}^{1}\hspace*{-.5mm}P_{1}^{{\rm o}}~(90.0\%)$            & $2.033261$ & $2.033256$ &  &
   &                  &                                                &         &         &             \\
\hline
\end{tabular}
\tablefoot{For brevity, we show only the core excitations
that are below the dominant $\rm 3p^6({}^1S_{0})\to 3p^53d({}^1P_{1}^{{\rm o}})$ threshold.
The exception is the $\rm 3p^54d\;({}^1P_{1}^{{\rm o}})$ threshold in \ion{K}{ii} whose
configuration is marked as questionable by \cite{Sugar:1985} and only recently
properly identified by \cite{Pettersen:2007}.
    \tablefoottext{a}{present work: 51-level (${\rm K}^{+}$) and 69-level (${\rm Ca}^{2+}$) MCBP results;}
    \tablefoottext{b}{UV spark spectroscopy experimental data of \cite{Pettersen:2007};}
    \tablefoottext{c}{MCHF results of \cite{Irimia:2003};}
    \tablefoottext{d}{critically compiled experimental data of \cite{Sugar:1985};}
   \tablefoottext{\bigstar}{dominant excitation threshold -- see Table~\ref{Tab:tar-rad}.}}\vspace*{2mm}
\end{table}