After a brief introduction to second quantisation notation (section II), which is used extensively, I focus of the “four H’s”: the Hückel (or tight binding; section III), Hubbard (section IV), Heisenberg (section V) and Holstein (section VII) models. These models play central roles in our understanding of condensed matter, particularly for materials where electronic correlations are important, ...

Debye-Hückel (DH) theory is extended to treat two-component size- and charge-asymmetric primitive models, focusing primarily on the 1:1 additive hard-sphere electrolyte with, say, negative ion diameters a(--) larger than the positive ion diameters a(++). The treatment highlights the crucial importance of the charge-unbalanced "border zones" around each ion into which other ions of only one spec...

This work discusses the introduction of concentration dependency relative permittivity in context activity coefficient models at different stages derivation models. We evaluate an experimental correlation and Michelsen–Mollerup–Breil model for order to assess impact using these both Debye–Hückel Born equations. Our results show that effects introducing levels are significant quantitative. Using...

The Debye–Hückel Limiting Law (DHLL) correctly predicts the thermodynamic behavior of dilute electrolyte solutions. Most articles and books explain this law using Peter Debye Erich Hückel’s original formalism linearizing Poisson–Boltzmann equation for a simple model. Brilliant in its own right, approach does not fully which microstates contribute range theory. Notably, establish Energy Multipli...

Conformational flexibility and balance between Möbius aromatic and Hückel antiaromatic conformers in [28]hexaphyrins depend on N-fused structure and meso-aryl substituents, revealed by various spectroscopic methods. In particular, the existence of the two conformers has been confirmed for singly-N-fused [28]hexaphyrins by femtosecond time-resolved transient absorption spectroscopy.