The concept of Randic index has been extended recently for a digraph. We prove that $2R(G)\leq \mathcal{E}(G)\leq 2\sqrt{\Delta(G)} R(G)$, where $G$ is a digraph, and $R(G)$ denotes the Randic index, $\mathcal{E}(G)$ denotes the Nikiforov energy and $\Delta(G) $ denotes the maximum degree of $G$. In both inequalities we describe the graphs for which the equality holds.

翻译：Randic 索引的概念最近被扩展为用于编程。 我们证明2R( G)\leq\leq \ mathcal{E}( G)\leq 2\sqrt\ Delta( G)} R( G)$, 其中$G美元是编程, $R( G) 表示兰迪指数, $\ mathcal{E}( G) 表示Nikiforov 能源, $\ Delta( G) 美元表示$( G) 的最大程度。 在两种不平等中, 我们描述平等所支持的图表 。