In this work, for the range $frac{n-1}{n} < p leq 1$, we give a molecular reconstruction theorem for $H^p(mathbb{Z}^n)$. As an application of this result and the atomic decomposition developed by S. Boza and M. Carro in [Proc. R. Soc. Edinb., 132 A (1) (2002), 25-43], we prove that the discrete Riesz potential $I_{alpha}$ defined on $mathbb{Z}^n$ is a bounded operator $H^p(mathbb{Z}^n) to H^q(mathbb{Z}^n)$ for $frac{n-1}{n} < p <