Transition probabilities of the AgS(A[formula omitted][formula omitted] X[formula omitted]) emission including spin–orbit coupling effects and evidence of a novel band system

Abstract

A systematic spectroscopic work using multireference configuration interaction (MRCI) and coupled cluster (CC) calculations was performed in conjunction with large basis sets for AgS. As a result, a more accurate dissociation energy of 17,542 cm−1 is predicted for the X2Π using an analytical potential energy curve, including spin–orbit effects. The calculated energy separation Te(A)∼ 10,500 cm−1 suggests that the AgS(A2Σ+→ X2Π) band system is in near-IR. An unobserved 32Π→ X2Π band system is predicted with Einstein coefficient for spontaneous emission of the orders of 104–105 s−1 in the UV region (342 nm). The radiative lifetimes for the A2Σ+ are of the order of ∼100 microseconds. The AgS(A) state presents a possible predissociation channel caused by interactions with the quartet 14Σ− and 14Π states. The spin–orbit coupling effects are considered in this work by utilizing the Breit–Pauli operator. The present findings are good references for future spectroscopic research concerning heavy-element sulfides.