Knowledge Bank

Large graphical unitary group approach (GUGA) spin-orbit multireference configuration interaction (SOCI) singles and doubles calculations have been performed on $Am2+$, $AmO2+$, $Cmo2\mathrm{<mrow\; data-mjx-texclass="ORD">2+</mrow>}$, and $CmO2+$. The ground state of the americyl cation is $\delta u2\varphi u1\mathrm{<mrow\; data-mjx-texclass="ORD">4</mrow>}\Phi 3/2u$. The first ligand to metal charge transfer (LMCT) state is $3\sigma u1\delta u2\varphi u2\mathrm{<mrow\; data-mjx-texclass="ORD">6</mrow>}\Sigma 5/2u$. The ground and first LMCT states of the isoelectronic dioxoamericium (V) and curyl cations are $\delta u2\varphi u2\mathrm{<mrow\; data-mjx-texclass="ORD">5</mrow>}\Sigma 0+g+$ and $3\sigma u1\varphi u23\pi u1\mathrm{<mrow\; data-mjx-texclass="ORD">7</mrow>}\Pi 0+g$. The dioxocurium (V) cation ground state is $\delta u2\varphi u23\pi u1\mathrm{<mrow\; data-mjx-texclass="ORD">6</mrow>}\Pi 3/2u$. Agreement with experimental LMCT excitation energies is good. Other intense electronic transitions are $f\leftarrow f$. Recent software developments have enabled the calculation of electric dipole transition moments from GUGA SOCI $wavefunctionsa$. Tentative $assignmentsb$ of the $f\leftarrow f$ transitions have been reevaluated with the new soft ware. Calculations are planned to search for nonlinear minima of these ions. The actinides are modeled with relativistic effective core potentials and Gaussian correlation consistent double-zeta plus polarization (ce-PVDZ) basis sets.