dipole moment


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Dipole moment

A mathematical quantity characteristic of a dipole unit equal to the product of one of its charges times the vector distance separating the charges. The dipole moment μ associated with a distribution of

() 
electric charges qi is given by where r i is the vector to the charge qi. For systems with a net charge (for example, positive), the origin is taken at the mean position of the positive charges (and vice versa). Dipole moments have the dimensions coulomb-meters. Molecular dipole moments were previously expressed in debye units, where 1 debye = 3.336 × 10-30 C · m. See Dipole

McGraw-Hill Concise Encyclopedia of Physics. © 2002 by The McGraw-Hill Companies, Inc.

dipole moment

[′dī‚pōl ‚mō·mənt]
(electricity)
(electromagnetism)
(physical chemistry)
The vector sum of the bond moments in a molecule, a measure of the polarity of the molecule.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
The switchable electric dipole moment of ferroelectric materials could for example be used as a gate for the underlying 2D electron system in an artificial topological insulator.
Table 1: The dipole moments [mu] (D), the polarizability [alpha] (au), the average polarizability [[alpha].sub.tot] (esu), the anisotropy of the polarizability Aa (esu), and the first hyperpolarizability [[beta].sub.tot] (esu) of Tetrabromophenol blue and Bromoxylenol blue.
The forces on particles are calculated by (1) while the dipole moment have been modified using IDM every time step, and particle transportation can be easily solved for particle trajectories and final particle chains.
To characterise the polarity table 1 provides the dipole moments of the studied functional groups.
In first approximation, the dipole moment of a triatomic molecule may be solved by the technique of vector addition that describes the resulting dipole [micro]res of the sum of two dipole moments [[mu].sub.1] and [[mu].sub.2] that make between them an angle [theta] given by Equation 2.
Suzuki, "The electric dipole moment of the electron," Reviews of Modern Physics, vol.
The value of the phase difference between the induced dipole moment m, and the field vector E controls the magnitude of the torque, reaching maximum when the phase difference is 9"", and zero when the phase is zero.
where [gamma] is the angle between the transition dipole moment vector of the absorbing group and the chain axis of the molecule [11,12].
Here a Hertzian (small) dipole with dipole moment p directed to positive X axis, at altitude xo above the infinite, flat and lossy ground, radiates time-harmonic electromagnetic (EM) waves at angular frequency [omega] = 2[pi]f Here the relative complex permittivity of the ground is [[epsilon]'.sub.r] = [epsilon]'/[[epsilon].sub.0] = [[epsilon].sub.r] + i[sigma]/[omega][[epsilon].sub.0], a being the ground conductivity, f the frequency of radiation and [[epsilon].sub.0] = 8,854 x [10.sup.-12] F/m is the absolute permittivity in vacuum or air.
The magnetism arises from the magnetic dipole moment of unpaired electrons in the d- or f-orbitals.