CCSD(T) calculations of confined systems: In-crystal polarizabilities of F−, Cl−, O2 −, and S2 −

We explore dipole polarizabilities of the singly and doubly charged anions F−, Cl−, O2 −, and S2 − in an external, harmonic oscillator (HO) confining potential ∑i12ω2ri2. We find that in contrast to F− and Cl− those for O2 − and S2 − are unrealistically high due to the instability of the corresponding restricted Hartree-Fock (RHF) solutions. Yet, already a relatively weak HO confining potential stabilizes their RHF solutions and eliminates any possible broken-symmetry solutions. The coupled-cluster theory with single, double and noniterative triple excitations (CCSD(T)) then yields considerably reduced polarizabilities for O2 − and S2 − relative to their unconfined values. We showed that polarizabilities of O2 − and S2 − are more sensitive to the strength of a confinement potential than are those for F− and Cl−. This enables us to relate the confining parameter ω with the known experimental polarizabilities for selected crystals (our “training set”) and to find a specific confining parameter ω for which t...