Calculate complex relative permittivity for a material

[ZeroResistance]

I need to calculate the dielectric heating power for a paricular material.
From here https://en.wikipedia.org/wiki/Dielectric_heating I got the formula for heating power is

\$Q = \omega \cdot \epsilon^{''}_{_{r}}\cdot \epsilon_{0} \cdot E^{2}\$

I get other parts but am stuck on
\$\epsilon^{''}_{_{r}}\$ which wiki says is the "is the imaginary part of the complex relative permittivity of the absorbing material".

[iMo]

It seems you better have to find a more simplified version of the formula, as the one you try elaborate is pretty difficult to mess with. Look at "Complex Permittivity" on wikipedia.

[ZeroResistance]

It seems you better have to find a more simplified version of the formula, as the one you try elaborate is pretty difficult to mess with. Look at "Complex Permittivity" on wikipedia.

OK, but say I have additional parameters regarding the material
1. the relative permittivity
2. The dielectric loss tangent (\$tan \delta\$)

Is it possible to derive "Epsilon R double dash" from these?

[iMo]

epsilon_double_dash (function of omega) = |D0/E0|*sin(delta)
Still the whole stuff is not manageable easily, imho. There must be some engineering tables or simple equations available too..