Knowledge Bank

The weakly bound complex $Ca+-Ar2$ produced by laser ablation in a pulsed nozzle cluster is studied with mass-selected resonance enhanced photodissociation spectroscopy. A short doublet progression. ($\omega e\prime =82.07cm-1$) to the blue of the $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}D\leftarrow 2S$ atomic transition is assigned to the $D2\Pi r,\leftarrow X2\Sigma +$ system. Spin-orbit splitting ($A=19.67cm-1$) of the doublets suggests a linear geometry: A peak observed at $13956cm-1$ is assigned the $C2\Sigma r\leftarrow X2\Sigma +$ system. No systems are detected from the derived atomic transition $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}P\leftarrow 2S$ in this complex. Additionally, complexes with more than two rare-gas ligands were probed and showed no sharp structure. M$\oslash$ller-Plesset second-order perturbation theory was used to determine the $Ca+-Ar2$ bond distances ($re$) of 3.064 \AA and a dissociation energy $(De)$ for atomization of 4.864 kcal/mol ($Ca+-Ar2\to Ca++2Ar$). This calculation included the correlation of the valence and core electron using a generated basis set for calcium and the aug-ccVQZ basis set for the argon atoms, resulting in a total of 271 basis functions for the calculations.