Ferromagnetic bond of Li10 cluster: An alternative approach in terms of effective ferromagnetic sites

Abstract

In this work, a model to explain the unusual stability of atomic lithium clusters in their highest spin multiplicity is presented and used to describe the ferromagnetic bonding of high-spin Li10 and Li8 clusters. The model associates the (lack of-)fitness of Heisenberg Hamiltonian with the degree of (de-)localization of the valence electrons in the cluster. It is shown that a regular Heisenberg Hamiltonian with four coupling constants cannot fully explain the energy of the different spin states. However, a more simple model in which electrons are located not at the position of the nuclei but at the position of the attractors of the electron localization function succeeds in explaining the energy spectrum and, at the same time, explains the ferromagnetic bond found by Shaik using arguments of valence bond theory. In this way, two different points of view, one more often used in physics, the Heisenberg model, and the other in chemistry, valence bond, come to the same answer to explain those atypical bonds.

Electronic structure of first and second row atoms under harmonic confinement

“…Similarly, Li under pressure would readily form antiferromagnetic bonds, which are sustained by the ability of Li to adopt a 1s 2 2p configuration. [58,59] Interestingly, at large ω, the ground state configurations of Li and Be are the same of the three and four-electron harmoniums, respectively. [21] This is expected because for large confinement the harmonic potential dominates over the Coulomb one.…”

“…For instance, Be under pressure would be a very reactive species able of sp hybridization that would resemble boron. Similarly, Li under pressure would readily form antiferromagnetic bonds, which are sustained by the ability of Li to adopt a 1 s 2 2 p configuration . Interestingly, at large ω , the ground state configurations of Li and Be are the same of the three and four‐electron harmoniums, respectively .…”

The change in the nature of bonding in the Li2 dimer under confinement

“…That is, the “ferromagnetic” state becomes more stable than the singlet which has the two valence electrons paired. This is not to be confused with the no‐pair ferromagnetic bonding 3 Li 2 introduced by Shaik et al [48–55], where the high‐spin structure has the symmetry .…”

“…That is, the "ferromagnetic" state becomes more stable than the singlet which has the two valence electrons paired. This is not to be confused with the no-pair ferromagnetic bonding 3 Li 2 introduced by Shaik et al [48][49][50][51][52][53][54][55], where the high-spin structure has the symmetry 3 Σ + u . A state averaged CASSCF(2,4) calculation for the singlet configuration at the (CCSD) critical confinement, ω = 0.316, reveals two states with energies −370.2 eV ( 1 Σ + g ) and −368.6 eV ( 1 Π u ).…”

From Infection Clusters to Metal Clusters: Significance of the Lowest Occupied Molecular Orbital (LOMO)

“…Such nanoclusters can potentially nucleate Li dendrites, leading to device failure. Based not only on such a practical point of view but also on fundamental interest, Li clusters have attracted researchers’ attention. − Also, high-spin Li clusters have caught the attention of theoreticians because of their novel bonding motifs. − …”