A classic case of Jahn–Teller effect theory revisited: Ab initio simulation of hyperfine coupling and pseudorotational tunneling in the 12E′ state of Na3

Abstract

a b s t r a c tThe predictive capabilities of current ab initio approaches are tested in a benchmark study on the well known case of the Na 3 ground state. This molecule is small enough to be treated with computationally demanding methods, but also shows an interesting interplay between Jahn-Teller-, spin-orbit-, rovibrational-and hyperfine-interactions. The necessary parameters for the effective Hamiltonian are derived from the potential energy surface of the 1 2 E 0 ground state and from spin density evaluations at selected geometries, without any fitting adjustments to experimental data. We compare our results to highly resolved microwave spectra, with the aim to improve previous assignment attempts, where some parameters had to be estimated from fits to measured spectra.

Complexes formed in collisions between ultracold alkali-metal diatomic molecules and atoms

“…These results accord with a physical picture in which relatively little spin density is located in p orbitals. However, a molecular-beam microwave study on Na 3 [121] suggests that the Fermi contact interactions are much smaller than the ESR spin densities imply, and this is supported by electronic structure calculations [122]. These details do not affect the basic physics discussed in the present paper: the important feature is that the spin densities shift substantially between atoms as a function of wide-amplitude motions.…”

Jahn–Teller and Pseudo-Jahn–Teller Effects: From Particular Features to General Tools in Exploring Molecular and Solid State Properties

“…The theoretical background of all these effects in atomic systems emerges from the first-principles as a delicate addition to the coupling between the electronic states and nuclear displacements, which occurs beyond the adiabatic approximation (vibronic coupling). The theory of the JTE and PJTE with many of their manifestations in molecular and solid state properties are rather well studied and continues developing. − Less attention has been paid so far to the PJTE, especially to its use as a tool in the study of the structure and properties of polyatomic syst...…”

“…As in any theoretical work, mathematical proofs of the origin of the JTE and PJTE structural instabilities based on first-principles are most important, but in detail they are of primary interest to more specialized readers and deserve separate consideration. For the more significant achievements in this field, see refs , , , and − for books; refs , , , and − for major reviews; refs − for JTE conference proceedings; and refs − …”

Towards photoassociation processes of ultracold rubidium trimers

“…Yet, these studies were restricted to light alkali metal species, i.e. Li, Na and K. Later, following the success of the helium droplet method, theoretical investigations of alkali trimer systems were reappearing -now also containing heavier elements such as Rb [34][35][36][37][38][39][40]. In these works, the main focus was on selected JT states and the reproduction of special transitions and spectra measured with He-droplet spectroscopy.…”

“…Previous theoretical studies on alkali trimers [25][26][27][28][29][30][31][32][33][34][35][36][37][38][39]43] were essentially restricted to either the doublet or quartet ground state or they investigated selected JT distorted excited states. Furthermore, we calculate the electronic dipole transition matrix elements between states.…”