Single- versus multi-state DIM model for RgX2 systems: On the influence of spin–orbit coupling on Ar–I2 potentials

摘要: Abstract A diatomics-in-molecule model is developed for rare gas–dihalogen systems with spin–orbit coupling included within the atoms-in-molecule scheme using LS -representation basis set. This approach found to provide good agreement both direct ab initio results and experimental data iodine molecule. Potential energy surfaces (PES) interaction of Ar( 1 S 0 ) I 2 in ground lowest-lying excited states (including B u + , ′2 are calculated. Because relatively large separations associated nonrelativistic at their equilibrium distances, mixing by Ar perturb rather weakly corresponding Ar–I PES, which can thus be represented simple analytic expressions. Perturbative corrections proposed case mixed strongly. Topologies lowest state PES differ from predictions previous models, particularly concerning existence a well linear geometry. Such depth comparable that T-shaped geometry obtained ( X g shallow ), particular. The remaining deviations calculated parameters values assigned distortions electronic structure atoms molecule, not taken into account traditional DIM treatment. effect these on topology discussed.