Estudo teórico dos radicais monocloreto de arsênio (AsCl0,+) e espectro fotoeletrônico

Abstract

There has been a rising interest on diatomic species in relation to their bonding schemes, especially those that involve elements of group 15 and halogens. They are isovalent to O2 molecule i.e. they have similar valence orbitals and thus have the same electronic states with the same energy order. The characterization of the electronic states of the arsenic monochloride radical (AsCl0,+) was performed using the multireference configuration interaction method with estimation of the effect of quadruple excitations (MRCI+Q) from the orbital reference optimized by the complete active space self-consistent field (CASSCF) method. The 4 electrons of the s valence orbitals of each atom were kept doubly occupied and we used 8 electrons in 8 molecular orbitals in the active space. The basis set functions used were the correlation- consistent polarized valence quintuple-ζ quality (aug-cc-pV5Z) added with diffuse functions, plus relativistic corrections as suggested by Douglas and Kroll (DK) for both atoms. Effects of spin-orbit coupling were also considered in all calculations. The spectroscopic constants calculated for each electronic state relative to the total energy of the system as a function of internuclear distance. We also calculated the vertical and adiabatic ionization potential and the theoretical photoelectron spectrum.