EN
In this work we present the explicit representations of the Voigt function K(a,b) (the convolution between a Gaussian and a Lorentzian function), the function N(a,b) defined as the convolution of Gaussian and dispersion distributions as well as the complex error function erf(a+ib), all in terms of the Kummer functions M(α,γ,a^2). The expansions are valid for all values of the parameter a (the relation between Lorentzian and Gaussian widths at the half maxima). Previous analytical works were known only when the parameter a≤1, or were based on numerical interpolations or empirical approximations. Also, new series and asymptotic expansions are presented.