
#1
Dec712, 05:07 AM

P: 241

Knowing the dielectric constant of a medium we can earn the electric field at any point in that medium which is deferent from the applied external electric field. So why do we use the Local field correction?




#2
Dec712, 07:51 AM

Mentor
P: 10,824

The dielectric constant is a macroscopic quantity  you get this value if you average the effects of many atoms/molecules. If you look closer, you might find small deviations from that average.




#3
Dec812, 04:58 PM

Sci Advisor
HW Helper
P: 1,935

There are huge differences from the average.
E gets huge and changes sign near atoms. 



#4
Dec912, 03:16 AM

Sci Advisor
P: 3,371

Why do we use Local field correction?
You can include local field corrections by working with a dielectric function which includes spatial dispersion. In the case of a homogeneous medium, this means that epsilon is a tensor which depends on frequency omega and wavevector k.




#5
Dec912, 05:08 PM

P: 241

[QUOTE=DrDu;4190199]You can include local field corrections by working with a dielectric function which includes spatial dispersion. In the case of a homogeneous medium, this means that epsilon is a tensor which depends on frequency omega and wavevector k.[/QUOTE
By this, do you mean that we can also include local field correction in the dielectric constant? 



#6
Dec1012, 02:15 AM

Sci Advisor
P: 3,371




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