Lagrange-like spectrum of perfect additive complements

Two infinite sets $A$ and $B$ of non-negative integers are called \emph{perfect additive complements of non-negative integers}, if every non-negative integer can be uniquely expressed as the sum of elements from $A$ and $B$. In this paper, we define a Lagrange-like spectrum of the perfect additive complements ($\mathfrak{L}$ for short). As a main result, we obtain the smallest accumulation point of the set $\mathfrak{L}$ and prove that the set $\mathfrak{L}$ is closed. Other related results and problems are also contained.