Program Package for the Calculation of Origin-Independent Electron Current Density and Derived Magnetic Properties in Molecular Systems

Monaco, Guglielmo; Summa, Francesco Ferdinando; Zanasi, Riccardo

doi:10.1021/acs.jcim.0c01136

Cited by 73 publications

(90 citation statements)

References 87 publications

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“…At variance with a yy , the magnitude of

κ_{yy}^{'} ((), ω)

in Figure 6, for ω = 0.077278 a.u., is quite large for ϕ ≠ 90°, with a maximum (minimum) in the vicinity of ϕ = 40° ( ϕ = 150°). Extremum points of

κ_{yy}^{'} ((), ω)

for ω = 0.128347 a.u., are found approximately in the same range of ϕ values.Large oscillations of

κ_{xx}^{'} ((), ω)

and

κ_{zz}^{'} ((), ω)

are observed in Figure S8 for ϕ ≈ 35° and ϕ ≈ 145°, suggesting the presence of a resonant frequency, which was confirmed by a computation with the SYSMOIC code 83 . We determined a singlet excitation at 3.5197 eV, corresponding to 352.26 nm, quite close to 355.001 nm, corresponding to 0.128347 a.u., with

ω = E_{h} / normalℏ = 4.134137336 \times 10^{16}

.…”

Section: Discussionsupporting

confidence: 69%

“…Large oscillations of

κ_{xx}^{'} ((), ω)

and

κ_{zz}^{'} ((), ω)

ω = E_{h} / normalℏ = 4.134137336 \times 10^{16}

.…”

Section: Discussionsupporting

confidence: 69%

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Physical achirality in geometrically chiral rotamers of hydrazine and boranylborane molecules

et al. 2021

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The diagonal components and the trace of tensors which account for chiroptical response of the hydrazine molecule N2H4, that is, static anapole magnetizability and frequency‐dependent electric dipole‐magnetic dipole polarisability, are a function of the ϕ≡∠ H─N─N─H dihedral angle. They vanish for symmetry reasons at ϕ = 0° and ϕ = 180°, corresponding respectively to C2v and C2h point group symmetries, that is, cis and trans conformers characterized by the presence of molecular symmetry planes. Nonetheless, vanishing diagonal components have been observed also in the proximity of ∠ H─N─N─H = 90°, in which the point group symmetry is C2 and hydrazine is unquestionably chiral. In the boranylborane molecule B2H4, assuming the B─B bond in the y direction, the ayy component of the anapole magnetizability tensor approximately vanishes for dihedral angles ∠ H─B─B─H corresponding to chiral rotamers which belong to D2 symmetry. Such anomalous effects have been ascribed to physical achirality of these conformers, that is, to their inability to sustain electronic current densities inducing either anapole moments, or electric and magnetic dipole moments, about the chiral axis connecting heavier atoms, as well as perpendicular directions. In other terms, the structure of certain geometrically chiral rotamers may be such that neither toroidal nor helical flow, which determine chiroptical phenomenology, can take place in the presence of perturbing fields parallel or orthogonal to the chiral axis.

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“…At variance with a yy , the magnitude of

κ_{yy}^{'} ((), ω)

in Figure 6, for ω = 0.077278 a.u., is quite large for ϕ ≠ 90°, with a maximum (minimum) in the vicinity of ϕ = 40° ( ϕ = 150°). Extremum points of

κ_{yy}^{'} ((), ω)

for ω = 0.128347 a.u., are found approximately in the same range of ϕ values.Large oscillations of

κ_{xx}^{'} ((), ω)

and

κ_{zz}^{'} ((), ω)

ω = E_{h} / normalℏ = 4.134137336 \times 10^{16}

.…”

Section: Discussionsupporting

confidence: 69%

“…Large oscillations of

κ_{xx}^{'} ((), ω)

and

κ_{zz}^{'} ((), ω)

ω = E_{h} / normalℏ = 4.134137336 \times 10^{16}

.…”

Section: Discussionsupporting

confidence: 69%

Physical achirality in geometrically chiral rotamers of hydrazine and boranylborane molecules

et al. 2021

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“…In our implementation, transition amplitudes

and

and corresponding transition energies

are obtained by means of a TD–HF≡RPA (or TD–DFT ) calculation. The full procedure for computing frequency dependent MEMDP densities has been implemented within the freely available SYSMOIC program package [ 59 ].…”

Section: Methodsmentioning

confidence: 99%

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

et al. 2021

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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.

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“…When a numerical representation of the current density is gauge-origin independent, the calculated NMR chemical shifts obtained with the integration approach are also independent of the gauge origin. We use the GIMIC method [29][30][31][32] for calculating current densities, however, the CTOCD approach also leads to gauge-origin independence [2,4,[42][43][44]. The spatial distribution of the shielding density provides detailed information about the origin of the individual elements of the nuclear magnetic shielding tensor, as well as the shielding constants [5,[44][45][46][47][48][49][50].…”

Section: Theorymentioning

confidence: 99%

“…He is one of the pioneers in the field of current-density calculations with his first article from 1981 on the ring-current model of the cyclopropenyl cation [1]. The "continuous transformation of the origin of the current density (CTOCD) method" from 1994 [2], which Keith and Bader called "continuous set of gauge transformations (CSGT)", was the starting point for the SYSMO and SYSMOIC program packages [3,4]. Professor Zanasi has published about 70 scientific articles on computational studies of magnetically induced current densities in molecules with "current density" in the title.…”

Section: Introductionmentioning

confidence: 99%

Spatial Contributions to 1H NMR Chemical Shifts of Free-Base Porphyrinoids

et al. 2021

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A recently developed methodology for calculating, analyzing, and visualizing nuclear magnetic shielding densities is used for studying spatial contributions including ring-current contributions to 1H nuclear magnetic resonance (NMR) chemical shifts of aromatic and anti-aromatic free-base porphyrinoids. Our approach allows a visual inspection of the spatial origin of the positive (shielding) and negative (deshielding) contributions to the nuclear magnetic shielding constants. Diatropic and paratropic current-density fluxes yield both shielding and deshielding contributions implying that not merely the tropicity of the current density determines whether the contribution has a shielding or deshielding character. Instead the shielding or deshielding contribution is determined by the direction of the current-density flux with respect to the studied nucleus.

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Program Package for the Calculation of Origin-Independent Electron Current Density and Derived Magnetic Properties in Molecular Systems

Cited by 73 publications

References 87 publications

Physical achirality in geometrically chiral rotamers of hydrazine and boranylborane molecules

Physical achirality in geometrically chiral rotamers of hydrazine and boranylborane molecules

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

Spatial Contributions to 1H NMR Chemical Shifts of Free-Base Porphyrinoids

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