Subject: dielectric at the atomic level

From: Barbara Nissen <[email-masked]>
Date: Tue, 26 Jan 1999 18:36:56 +0100

Dear Colleagues,

The Clausius-Mossotti equation relates to the bulk material.   Has
anyone encounered its use (with or without mdification) at the atomic
level, please?   Thank you.   

Barbara

-- 

Dr Barbara Nissen 
Inst. of Low Temperature and Structure Research,  PAS
2 Okolna Str., 50-950 Wroclaw, P.O. Box 937, Poland
Tel +48 -(0)71- 34 350 21,  Fax. +48-(0)71-44 10 29

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From: Arno Papazyan <[email-masked]>
Date: Tue, 26 Jan 1999 15:53:43 -0800 (PST)

Dear Barbara,
Clausius-Mossotti equation actually relates a bulk property (dielectric
constant) to "microscopic properties" summarized as a "polarity
parameter". The "polarity parameter" is actually a generalizable concept
that can represent a material with permanant dipoles, or simply
polarizability. So we have,

(eps-1)/(eps+2) = 4/3 Pi eta

where

eta = rho mu^2 / (3 kT)  for constituent particles with permanent dipoles
eta = rho alpha  for constituent particles with polarizabilities only

rho is the number density of particles, alpha is "particle"
polarizability, mu is permanent dipole magnitude, k is Boltzmann constant,
T is absolute temperature, Pi is 3.14... and eps is the bulk dielectric
constant. 

Of course, one has to use the Clausius-Mossotti equation where it actually
applies.

I don't know if I actually answered your question, but I hope this was
helpful.

Best regards,
Arno Papazyan

On Tue, 26 Jan 1999, Barbara Nissen wrote:

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