On the SmCo dimer: a detailed density functional theory analysis

Making use of 21 different exchange-correlation functionals, we performed density functional theory calculations, within the effective core potential level, to investigate some spectroscopic and electronic features of the SmCo dimer in its ground state. A particular emphasis was placed on the (spin) multiplicity of SmCo. Most of the functionals under discussion unanimously agreed that the multiplicity of SmCo should be 10. It was observed that the nature of interaction between Sm and Co atoms to form the SmCo dimer can be described, to a good approximation, by a Lennard-Jones curve. For the multiplicity value 10, the binding energy D(e) was seen to be in the range 1.08-1.77 eV, while the equilibrium separation distance and the fundamental frequency were found to be r(e) = 2.975 +/- 0.035 A and omega(e) = 120 +/- 10 cm(-1), respectively.