Electron localisation function in current-density-functional theory

Abstract

We present a generalisation of the electron localisation function (ELF) to current-densityfunctional theory as a descriptor for the properties of molecules in the presence of magnetic fields. The resulting current ELF (cELF) is examined for a range of small molecular systems in field strengths up to B 0 = 235 kT (one atomic unit). The cELF clearly depicts the compression of the molecular electronic structure in the directions perpendicular to the applied field and exhibits a structure similar to that of the physical current densities. A topological analysis is performed to examine the changes in chemical bonding upon application of a magnetic field.

Information on Gas‐Phase Diatomic Molecules from Magnetically Induced Current Densities

“…The work by Teale and coworkers presented a new electron localization function (ELF) for systems in magnetic fields. [23] This function, called cELF, is a tool for analyzing the changes occurring in chemical bonds on application of a magnetic field. The idea is based on the phenomenon of "perpendicular paramagnetic bonding" in diatomic molecules-a new type of molecular bond caused by extremely high magnetic fields, likely to exist near white dwarf stars.…”

“…However, as explained by Teale et al this bonding mechanism is less evident for covalent systems. [23] The present study follows a different approach, where the perturbing magnetic field is infinitely weak; this choice is due to the fact that the MICD is a response property, that is, that appears in the presence of an infinitely weak magnetic field. The present work explores the type of information that the consideration of MICDs can provide for the simplest bonded molecular systems-diatomic molecules, that is, systems containing only one chemical bond.…”

“…However, as explained by Teale et al this bonding mechanism is less evident for covalent systems. [23] The present study follows a different approach, where the perturbing magnetic field is infinitely weak; this choice is due to the fact that the MICD is a response property, that is, that appears in the presence of an infinitely weak magnetic field.…”

Density Functional Theories and Coordination Chemistry

“…Other more specific tools based on the fractional occupation number weighted density, 194 electron localization functions (ELF) 195 or KS energy decomposition 196 have been developed for a qualitative analysis of complicated electronic structure solutions.…”

Orbital-free photophysical descriptors to predict directional excitations in metal-based photosensitizers

“…In order to circumvent these limitations, universal orbitalfree molecular descriptors are highly commendable and a large body of groups have worked on the development of density-based descriptors in the last decade. [21][22][23][24][25][26][27][28][29][30][31][32][33] Particular effort has been spent on quantifying the overall amount of charge transfer including its effect on excitation energies. 34,35 However, a more ne-grained picture is advantageous for multichromophoric systems, such as transition metal complexes, where a fragment-based analysis approach 36,37 was shown to be particularly powerful.…”