For the Fourier coefficients of , see Ramanujan tau function.

The constants e₁, e₂ and e₃

, and are usually used to denote the values of the -function at the half-periods.

They are pairwise distinct and only depend on the lattice and not on its generators.

, and are the roots of the cubic polynomial and are related by the equation:

Because those roots are distinct the discriminant does not vanish on the upper half