scholarly journals Study of Refractive Index and Birefringence Variation near the Surface of LiNbO3 Open Type Optical Waveguide using Point Dipole Approximation

2021 ◽  
Vol 1817 (1) ◽  
pp. 012024
Author(s):  
Velagapudi Suhasini ◽  
I.V. Subbareddy ◽  
Pasunooti Manoher ◽  
V. Srinivasa Rao ◽  
R. Ethiraj
Keyword(s):  
Refractive Index ◽  
Optical Waveguide ◽  
Dipole Approximation ◽  
Point Dipole ◽  
Open Type ◽  
Point Dipole Approximation

NEW FORMULATION FOR NON-EQUILIBRIUM SOLVATION: SPECTRAL SHIFTS AND CAVITY RADII OF 6-PROPANOYL-2-(N,N-DIMETHYLAMINO) NAPHTHALENE AND 4-(N,N-DIMETHYLAMINO) BENZONITRILE

2006 ◽  
Vol 05 (spec01) ◽  
pp. 355-374 ◽  
Author(s):  
YAO HUANG ◽  
XIANG-YUAN LI ◽  
KE-XIANG FU ◽  
QUAN ZHU
Keyword(s):  
Density Functional ◽  
Multipole Expansion ◽  
Dipole Approximation ◽  
Point Dipole ◽  
Functional Theory ◽  
Spectral Shifts ◽  
Point Dipole Approximation ◽  
Accessible Surface ◽  
New Formulation ◽  
Solvent Accessible Surface

In the present work, the new formulations describing spectral shifts by the authors have been introduced and employed to investigate two dye molecules, 6-propanoyl-2-(N,N-dimethylamino) naphthalene and 4-(N,N-dimethylamino) benzonitrile. From the viewpoints of the authors, the cavity radii were overestimated owing to the errors existing in the traditional models. Slightly differing from the results by other authors in the past, this work fits the cavity radii to the values of ~4.5 Å for 6-propanoyl-2-(N,N-dimethylamino) naphthalene and ~3.2 Å for 4-(N,N-dimethylamino) benzonitrile. In the fittings, both point dipole approximation and multipole expansion methods are employed. The calculations of the excited states are performed by means of the time-dependent density functional theory. Comparing the fitted cavity radii from the experimental spectra with those estimated from the molecular volumes by some well-known procedures such as COSMO and PCM, we find that the new formulations give fairly satisfactory results. By taking an atomic ion as an example, the authors argue that the Onsager radii recommended by some popular procedures are greatly exaggerated. The cavity radius derived simply from the volume encompassed by the solvent-accessible surface, without any addition of other parts, is suggested for application.

Direct Simulation of Electrorheological Suspensions

2004 ◽  
Author(s):  
Pushpendra Singh ◽  
Nadine Aubry
Keyword(s):  
Stress Tensor ◽  
Electric Fields ◽  
Electrostatic Force ◽  
Dipole Approximation ◽  
Point Dipole ◽  
Maxwell Stress ◽  
Particle Interactions ◽  
Maxwell Stress Tensor ◽  
Point Dipole Approximation ◽  
Electrorheological Suspensions

A numerical scheme based on the distributed Lagrange multiplier method (DLM) is used to study the motion of particles of a dielectric suspensions subjected to uniform and nonuniform electric fields. The Maxwell stress tensor method is used for computing electrostatic forces. In the point dipole approximation the total electrostatic force acting on a particle can be divided into two distinct contributions, one due to dielectrophoresis and the second due to particle-particle interactions. The former is zero when the applied electric field is uniform and the latter depends on the distance between the particles. In the Maxwell stress tensor approach these two contribution appear together. Simulations show that as expected the error in the point dipole approximation decreases, as the distance between the particles increases.

scholarly journals Point-dipole approximation for small systems of strongly coupled radiating nanorods

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Derek W. Watson ◽  
Stewart D. Jenkins ◽  
Vassili A. Fedotov ◽  
Janne Ruostekoski
Keyword(s):  
Dipole Approximation ◽  
Point Dipole ◽  
Small Systems ◽  
Strongly Coupled ◽  
Point Dipole Approximation
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