Let Fn denote the distribution function of the normalized sum Zn=(X1+⋯+Xn)/σn of i.i.d. random variables with finite fourth
absolute moment. In this paper, polynomial rates of convergence of Fn to the
normal law with respect to the Kolmogorov distance, as well as polynomial
approximations of Fn by the Edgeworth corrections (modulo logarithmically
growing factors in n) are given in terms of the characteristic function of
X1. Particular cases of the problem are discussed in connection with
Diophantine approximations