Electronic Currents Induced by Optical Fields and Rotatory Power Density in Chiral Molecules

Abstract

The electric dipole–magnetic dipole polarizability tensor κ′, introduced to interpret the optical activity of chiral molecules, has been expressed in terms of a series of density functions kαβ′, which can be integrated all over the three-dimensional space to evaluate components καβ′ and trace καα′. A computational approach to kαβ′, based on frequency-dependent electronic current densities induced by monochromatic light shining on a probe molecule, has been developed. The dependence of kαβ′ on the origin of the coordinate system has been investigated in connection with the corresponding change of καβ′. It is shown that only the trace kαα′ of the density function defined via dynamic current density evaluated using the continuous translation of the origin of the coordinate system is invariant of the origin. Accordingly, this function is recommended as a tool that is quite useful for determining the molecular domains that determine optical activity to a major extent. A series of computations on the hydrogen peroxide molecule, for a number of different HO–OH dihedral angles, is shown to provide a pictorial documentation of the proposed method.

Electronic Currents and Anapolar Response Induced in Molecules by Monochromatic Light

“…Both basis sets have been downloaded from BSE [33,34]. In our implementation, outlined in detail in a previous reference [35], transition amplitudes S j and T j and corresponding transition energies have been obtained by means of TD-HF calculations. The complete procedure for computing frequency dependent anapole polarizabilities f αβ and anapole magnetizabilities a αβ has been coded within the freely available SYSMOIC program package [36].…”

“…Therefore, for the anapole magnetizability (41), only a few terms of those appearing in Equation (93) of Ref. [9] are recovered, for the reasons explained in the discussion following Equation (35).…”

Spin Currents Induced in Open-Shell Molecules by Static and Uniform Magnetic and Electric Fields in the Presence of a Spin–Orbit Coupling Interaction and Conservation Law

“…In the SI system, units of J are [ Am − 2 ] . As stated before, the results here proposed are to be taken into account only in the presence of static and uniform magnetic and electric fields, so dynamic currents are not considered. − The Hamiltonian describes the interaction with the intramolecular perturbation, that is, the intrinsic magnetic dipoles μ a = γ a I a , expressed via the magnetogyric ratio γ a = g μ N normalℏ = g e 2 m normalp and spin bold-italicI a = normalℏ 2 n a , with n a an integer, of nucleus a via the vector potential ∑ a = 1 N bold-italicA bold-italicμ a , and with an external, spatially uniform and time-independent magnetic field bold-italicB = bold∇ × A B bold-italicA = bold-italicA bold-italicB + ∑ a = 1 N A μ…”

On the computation of frequency‐dependent molecular magnetizabilities via dynamical charge and current electron densities

“…29,30 Origin invariant diagonal components of MEMDP can be computed via ad hoc techniques [31][32][33] and, more recently, an origin invariant rotatory power density has also been evaluated in a few chiral compounds. 34 Nonetheless, no generally accepted solution has yet been proposed to the problem of computing dynamical magnetizabilities 35,36 and related properties 37,38 via methods of time-dependent perturbation theory 39 : the extension of GIAO techniques to frequencydependent electromagnetic fields is nontrivial. No origin-independent expression of the FDM has been found in the relativistic domain.…”