Consider the set of all graphic sequences with $n$ elements as a subset of $\mathbb{R}^{n}$, namely let $$D(n)=\{(d_{1},\dots,d_{n})\in\mathbb{Z}_{+}^{n}:d_{1}\geq\dots\geq d_{n},\ \sum_{i=1}^{n}d_{i}\ \text{is even},\ \sum_{i=1}^{k}d_{i}\leq k(k-1)+\sum_{i=k+1}^{n}\min\{k,d_{i}\}\ \text{for all}\ 1\leq k\leq n \}.$$ One can observe that the diameter of $D(n)$ equals $(n-1)\sqrt[]{n}$. The question is:

How to compute the volume of the convex hull of $D(n)$?