The debye (symbol: D) is a CGS unit (a nonSI metric unit) of electric dipole moment named in honour of the physicist Peter J. W. Debye. It is defined as 1×10−18 statcoulombcentimetre. Historically the debye was defined as the dipole moment resulting from two charges of opposite sign but an equal magnitude of 1010 statcoulomb (generally called e.s.u. (electrostatic unit) in older literature), which were separated by 1 ångström. This gave a convenient unit for molecular dipole moments.

1 D = 1018 statC·cm = 1010 esu·Å = 1⁄_{299,792,458}×10−21 C·m ≈ 3.33564×10−30 C·m ≈ 1.10048498×1023 q_{P}l_{P} ≈ 0.393430307 ea_{0} ≈ 0.20819434 eÅ
Typical dipole moments for simple diatomic molecules are in the range of 0 to 11 D. Symmetric homoatomic species, e.g. chlorine, Cl_{2}, have zero dipole moment and highly ionic molecular species have a very large dipole moment, e.g. gas phase potassium bromide, KBr, with a dipole moment of 10.5 D.
The debye is still used in atomic physics and chemistry because SI units are inconveniently large. The smallest SI unit of electric dipole moment is the yoctocoulombmetre, which is roughly 300,000 D. There is currently no satisfactory solution to this problem of notation without resorting to the use of scientific notation.
Other articles related to "debye":
... One such Extended DebyeHückel Equation is given by where as its common logarithm is the activity coefficient, is the integer charge of the ion (1 for H+, 2 for Mg2+ etc.), is the ionic strength of the aqueous ... The Extended DebyeHückel Equation provides accurate results for μ ≤ 0.1 M ... The DebyeHückel Equation cannot be used in the solutions of surfactants where the presence of micelles influences on the electrochemical properties of the system (even rough judgement overestimates ...
... The Debye–Hückel theory was proposed by Peter Debye and Erich Hückel as a theoretical explanation for departures from ideality in solutions of electrolytes ... The DebyeHückel equation provides a starting point for modern treatments of nonideality of electrolyte solutions ...
... This is equivalent to 1 DebyeAngstrom, where 1 Debye = 1×10−18 statcoulombcentimetre is the cgs unit of molecular dipole moment and 1 Angstrom = 1×10−8 cm ... moment resulting from two opposing dipole moments but an equal magnitude of 1 Debye which are separated by a distance of 1 Angstrom, a typical bond length ... This is analogous to the Debye unit for the dipole moment of two opposing charges of 1×10−10 statcoulomb separated by 1 Angstrom, and the name Buckingham was in fact ...
... The Peter Debye Award in Physical Chemistry is awarded annually by the American Chemical Society "to encourage and reward outstanding research in physical chemistry" ... The award is named after Peter Debye and granted without regard to age or nationality ...
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