Ground state of the lithium atom in strong magnetic fields

Abstract

The ground and some excited states of the Li atom in external uniform magnetic fields are calculated by means of our two-dimensional mesh Hartree-Fock method for field strengths ranging from zero up to 2.35 ϫ10 8 T. With increasing field strength, the ground state undergoes two transitions involving three different electronic configurations: for weak fields, the ground-state configuration arises from the field-free 1s 2 2s configuration; for intermediate fields, it arises from the 1s 2 2p Ϫ1 configuration, and in high fields, the 1s2 p Ϫ1 3d Ϫ2 electronic configuration is responsible for the properties of the atom. The transition field strengths are determined. Calculations on the ground state of the Li ϩ ion allow us to describe the fielddependent ionization energy of the Li atom. Some general arguments on the ground states of multielectron atoms in strong magnetic fields are provided.

Beryllium in strong magnetic fields

“…This holds equally for the comparison of our data for finite field strengths with the more accurate results in Ref. [27,33] and it turns out that these are energetically higher up to one percent for γ = 10. For the first excited state 2 1 0 + a different behavior can be observed.…”

“…a crossover of several states individually representing the ground state of the atom for a certain interval of field strengths takes place. The orbital and spin Zeeman-terms are important for the identification of the field-dependent global ground state [27,28,33,39,40]. Beyond this the magnetically tightly bound orbitals [2,41] compared to the non-tightly bound orbitals/states play a central role for the determination of the ground state.…”

“…Thereby our knowledge on the electronic structure of the lithium atom in a strong magnetic field has been advanced significantly (for the state-of-the-art before this work see Refs. [24,25,26,27,28,29,30,31]). …”

Exchange and correlation energies of ground states of atoms and molecules in strong magnetic fields

“…The binding energy of this state increases monotonically with increasing field strength. A careful investigation shows [12] that there exist two crossovers with respect to the ground state of the Li atom with increasing field strength finally ending up in a spin quartett state. The first crossover occurs at B c1 = 0.176 up to which the 1 2 0 + remains the global ground state.…”

“…[10] and references therein). For the lithium atom there are two recent investigations [11,12] which cover also the intermediate regime of field strengths.…”