Theoretical studies on low-lying electronic states of the CCl+, SiCl+, and GeCl+ ions

Abstract

Potential energy curves for the ground state X 1Σ+ and low-lying A 1Π and a 3Π states of the CCl+, SiCl+, and GeCl+ ions have been calculated by ab initio LCAO–SCF–MO configuration interaction method. Calculated molecular constants Te, ωe, and ωexe agree well with available experimental data. The assignments of A 1Π–X 1Σ+ and a 3Π–X 1Σ+ bands for CCl+ and a 3Π–X 1Σ+ band for SiCl+ have been confirmed.

In search of molecular ions for optical cycling: a difficult road

“…Previous ab initio calculations predicted that the A 1 Π state is either weakly bound or dissociative and lies above the a 3 Π state. 123 Our calculations confirm the order of the two states with a 3 Π lying in the 3.5-4.0 eV range and A 1 Π lying in the 4.8-5.6…”

“…studied experimentally and theoretically. [120][121][122][123] In particular, these ions were detected as afterglows of the corresponding tetrachloride in a rare gas originating due to a 3 Π → X 1 Σ + emission in the UV range. Previous ab initio calculations predicted that the A 1 Π state is either weakly bound or dissociative and lies above the a 3 Π state.…”

In Search of Molecular Ions for Optical Cycling: A Difficult Road

“…The low-lying states of monochloride ions CCl + , SiCl + , and GeCl + have been previously studied experimentally and theoretically. [120][121][122][123] In particular, these ions were detected as afterglows of the corresponding tetrachloride in a rare gas originating due to a 3 Π → X 1 Σ + emission in the UV range. Previous ab initio calculations predicted that the A 1 Π state is either weakly bound or dissociative and lies above the a 3 Π state.…”

Translationally cold trapped CCl+ reactions with acetylene (C2H2)

“…Other computational studies on CCl + itself recommend using multireference methods. [46][47][48][49] The computational cost of using multireference methods for the larger potential energy surface would be prohibitive, therefore we use the CCSD/aug-cc-pVTZ level of theory, which gives reasonable agreement with previously published computational and experimental data for CCl + and C 2 H 2 separately. [46][47][48][49][50] Reported CCSD(T)/CBS energies should be accurate to within 0.04 eV.…”

“…[46][47][48][49] The computational cost of using multireference methods for the larger potential energy surface would be prohibitive, therefore we use the CCSD/aug-cc-pVTZ level of theory, which gives reasonable agreement with previously published computational and experimental data for CCl + and C 2 H 2 separately. [46][47][48][49][50] Reported CCSD(T)/CBS energies should be accurate to within 0.04 eV. Computations were compared to previous theoretical work and experimental data where available for the reactants and products in order to determine the best level of theory to determine accurate energetics.…”