Dipole moment: Difference between revisions

From SklogWiki
Jump to navigation Jump to search
m (...added category)
m (Slight tidy)
Line 1: Line 1:
The '''electric dipole moment''' is a measure of polarity. It is the second term in a multipole expansion of a field (the first one being the monopole, or Coulombic, term.) Its definition, for a system of point charges, is
The '''electric dipole moment''' is a measure of polarity. It is the second term in a multipole expansion of a field (the first one being the monopole, or Coulombic, term.) Its definition, for a system of point charges, is given by
<math>\mathbf{p} = \sum_{i=1}^N \, q_i \, \mathbf{r}_i.</math>
 
:<math>\mathbf{p} = \sum_{i=1}^N \, q_i \, \mathbf{r}_i.</math>


For molecular systems, it is customarily given in units of Debyes, after the physicist [[Peter J. W. Debye]].
For molecular systems, it is customarily given in units of Debyes, after the physicist [[Peter J. W. Debye]].

Revision as of 11:38, 5 June 2012

The electric dipole moment is a measure of polarity. It is the second term in a multipole expansion of a field (the first one being the monopole, or Coulombic, term.) Its definition, for a system of point charges, is given by

For molecular systems, it is customarily given in units of Debyes, after the physicist Peter J. W. Debye. In SI units, D equals approximately Coulomb-meter (exactly C m/s divided by , the speed of light in vacuum). Conversely, 1 C m = D. This is unit is convenient for molecular systems since 1ÅD.