Accurate calculation of electron affinity for S3**Project supported by the National Natural Science Foundation of China (Grant Nos. 11874179, 11447194,11574114, and 11874177) and the Natural Science Foundation of Jilin Province, China (Grant No. 20180101289JC).

Abstract

The accurate equilibrium structures of S3 and are determined by the coupled-cluster method with single, double excitation and perturbative triple excitation (CCSD(T)) with basis sets of aug-cc-pV(n + d)Z (n = T, Q, 5, or 6), complete basis set extrapolation functions with two-parameters and three-parameters, together with considering the contributions due to the core-valence electron correlation, scalar relativistic effects, spin–orbit coupling, and zero-point vibrational corrections. Our calculations show that both the neutral S3 and anion have open forms with C2v symmetry. On the basis of the stable geometries, the adiabatic electron affinity of S3 is determined to be 19041(11) cm−1, which is in excellent agreement with the experimental data (19059(7) cm−1). The dependence of geometries and electron affinity on the computation level and physical corrections is discussed. The present computational results are helpful to the experimental molecular spectroscopy and bonding of S3.