# Difference between revisions of "Dipole moment"

Carl McBride (talk | contribs) m (Slight tidy) |
Carl McBride (talk | contribs) m (Added a couple more significant figures) |
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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]]. | ||

− | In SI units, <math>1</math>D equals approximately <math>3.33564\times 10^{-30}</math> Coulomb-meter (exactly <math>10^{-21}</math>C m<math>^2</math>/s divided by <math>c</math>, the speed of light in vacuum). Conversely, 1 C m = <math>2.9979 10^{29}</math>D. This is unit is convenient for molecular systems since 1Å<math>\times 1 e=4. | + | In SI units, <math>1</math>D equals approximately <math>3.33564\times 10^{-30}</math> Coulomb-meter (exactly <math>10^{-21}</math>C m<math>^2</math>/s divided by <math>c</math>, the speed of light in vacuum). Conversely, 1 C m = <math>2.9979 10^{29}</math>D. This is unit is convenient for molecular systems since 1Å<math>\times 1 e=4.80320</math>D. |

[[category: Electrostatics]] | [[category: Electrostatics]] |

## Revision as of 11:15, 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.