Influence of chemical bonds on the lifetime of the molecular-field-split $2p$ levels in ${\mathrm{H}}_2\mathrm{S}$

Different lifetime broadenings in molecular-field-split $2p$ core levels in ${\mathrm{H}}_2\mathrm{S}$ are predicted theoretically and are identified in an experimental investigation of the $\mathrm{S}2p$ Auger electron spectrum. The measurements were performed for the transition to the vibrationally resolved $X^1{A}_1$ ground state of ${\mathrm{H}}_2{\mathrm{S}}^{2+}.$ The lifetimes of the ${3e}_{1/2}$ and ${5e}_{1/2}$ levels of the $2p$ ionized molecule are found to be 64 and 74 meV, respectively. This unambiguous determination of the lifetime difference of $10\pm 1\mathrm{meV}$ is only possible as the ${4e}_{1/2}\to X^1{A}_1{(2b}_1^{-2})$ decay channel that overlaps the ${5e}_{1/2}\to X^1{A}_1{(2b}_1^{-2})$ channel is practically suppressed in Auger decay in ${\mathrm{H}}_2\mathrm{S}.$ The lifetime difference is confirmed by ab initio calculations. A theoretical analysis shows that it results from the mutual orientation of the core hole in the intermediate states and the valence electron density in the sulfur $3p$ orbitals. Both are strongly influenced by the chemical bond. Thus the observed effect is the direct result of a fundamental property of molecular electronic structure.