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## Main Question or Discussion Point

I have come up with a paradox: Ionic crystals, in which cations and anions form a lattice, seems to have total electric dipole moment!

For example, consider a one dimensional example:

##+ - + - + - ... + - + -##

In the above picture, a ##+## represents a cation and a ##-## represents an anion.

So in calculating the total magnetic dipole moment, with the definition ##P=\int x \rho (x) dx##, I pair the ions and each cation anion pair have a dipole moment ##-ql##, where ##q## is charge and ##l## is the distance between the cation and anion. Then the total dipole moment is ##\frac{n}{2}ql##!

I don't think ionic crystals can have total dipole moment because if so, salt will have electric field around it!

Can anybody explain this to me?

For example, consider a one dimensional example:

##+ - + - + - ... + - + -##

In the above picture, a ##+## represents a cation and a ##-## represents an anion.

So in calculating the total magnetic dipole moment, with the definition ##P=\int x \rho (x) dx##, I pair the ions and each cation anion pair have a dipole moment ##-ql##, where ##q## is charge and ##l## is the distance between the cation and anion. Then the total dipole moment is ##\frac{n}{2}ql##!

I don't think ionic crystals can have total dipole moment because if so, salt will have electric field around it!

Can anybody explain this to me?