  In this paper we investigate some entanglement properties for the Hydrogen
molecule considered as a two interacting spin 1/2 (qubit) model. The
entanglement related to the $H_{2}$ molecule is evaluated both using the von
Neumann entropy and the Concurrence and it is compared with the corresponding
quantities for the two interacting spin system. Many aspects of these functions
are examinated employing in part analytical and, essentially, numerical
techniques. We have compared analogous results obtained by Huang and Kais a few
years ago. In this respect, some possible controversial situations are
presented and discussed.
