Bonding in some covalent derivatives of the 1,2,3,4-thiatriazole-5-thiolate anion. A topological study

With that in our mind, we undertook a topological analysis, based on the AIM theory, to gain more insight into the bonding in covalent derivatives of CS2N3- moiety, trying to find an explanation to the origin of the NH and S-H connectivities. The question is: which is the reason that makes all the covalent derivatives prefer the S-R connectivity while the hydracid has an N-H one?