Electron affinity of oganesson

The electron affinity (EA) of the superheavy element Og is calculated by the use of the relativistic Fock-space coupled cluster (FSCC) and configuration interaction methods. The FSCC cluster operator expansion includes single, double, and triple excitations treated in a nonperturbative manner. The Gaunt and retardation electron-electron interactions are taken into account. Both methods yield the results that are in agreement with each other. The quantum electrodynamics correction to the EA is evaluated using the model Lamb-shift operator approach. The electron affinity of Og is obtained to be 0.076(4) eV.

Figure 1

The EA for Og calculated with the $H_{\mathrm{GRECP}}$ Hamiltonian by means of the FSCC-SD method exploiting the basis set ${\chi }_0+{\gamma }_1^s$ versus the parameter $\zeta$ of the basis function ${\gamma }_1^s\left(\zeta \right)$ (eV).

Figure 2

The EA for Og calculated with the $H_{\mathrm{GRECP}}$ Hamiltonian by means of the FSCC-SD method for the subsequently enlarged basis sets ${\chi }_2^s, {\chi }_3^s$, and ${\chi }_4^s$ versus the parameter $\zeta$ of the basis functions ${\gamma }^s\left(\zeta \right)$ (eV). The basis set ${\chi }_1^s$ includes one optimized $s$-type basis function obtained on the previous stage of the optimization.

Figure 3

The EA for Og calculated with the $H_{\mathrm{GRECP}}$ Hamiltonian by means of the FSCC-SD method for the subsequently enlarged basis sets ${\chi }_1^i, {\chi }_2^i, {\chi }_3^i$, and ${\chi }_4^i$ versus the parameter $\zeta$ of the basis functions ${\gamma }_k^i\left(\zeta \right),k=1,\cdots ,4$ (eV). The basis set ${\chi }^h$ includes the optimized functions for all $L$ up to $h$.