Hybrid organic-inorganic networks, including three-dimensional metal-organic frameworks (MOFs) and one-or two-dimensional coordination polymers (CPs), have opened new application areas within solid state chemistry throughout the last few decades. The materials typically consist of metal-nodes connected by organic linkers, and in some cases include additional metallicnode centers, e.g., in perovskite structures. The majority of the discovered structures are crystalline and typically synthesized by hydrothermal processes, but recently it has been discovered that some members of this chemical family can form a stable liquid phase upon heating (prior to thermal decomposition), allowing subsequent supercooling into a glassy state. This work has opened a new glass family, notably distinct from the existing metallic, organic, and inorganic glasses, and with possible applications in, e.g., nuclear waste immobilization, thermoelectrics, gas separation, and energy storage, as well as the possibility to produce bulksized hybrid organic-inorganic samples (>1 cm 3 ) without grain boundaries. Although these hybrid glasses are chemically distinct from the traditional glass families, they share a number of structural similarities to chemically-ordered network glasses (e.g., oxides), as the metallic nodes (for oxides typically Si, Ge, P; for hybrids typically transition metals) bridge through single oxygens and large organic linkers for oxide and hybrid glasses, respectively. Similarly, the metal nodes in the two glass families share the same range of coordination numbers (typically 4-6). However, there is a major difference in the discovery and design of new glasses. Hybrid glasses are typically made by melt-quenching or ball-milling a specific crystal and thus restricted to stoichiometric compositions. On the other hand, the compositions of oxide glasses can be continuously adjusted through the addition of so-called modifiers or "fluxes" (e.g., alkali oxides), which result in the breakage of the continuous network structure of the pure network-forming oxide, thereby creating non-bridging oxygens, i.e., oxygens which will only covalently bond to one cationic node. This leads to changes in the physical properties, for example lowering of the melting and glass transition temperatures, hence enabling melting at significantly lower temperatures. The modifier addition in oxide glasses thus enables a chemical diversity that has led to a broad range of applications, from window glasses and touchscreen displays to nuclear waste immobilization, bioactive glasses, and pharmaceutical vials. As such, the possibility to tune the structure and properties of hybrid glasses through modifier addition has not yet been realized, although we note that some works have been devoted to co-melting of two MOFs and ionic liquid facilitated melting of ZIF-8 MOF. In this work, we present experimental and computational evidence for water acting as a modifier in a transition metal-based bis-acetamide hybrid coordination network glass (HCNG) of composition Co(hmba) 3[CoBr4], where hmba: N,N'-1,6-hexamethylenebis(acetamide). While we focus on the Co(hmba)3[CoBr4] system, we also confirm the effect of the modifier on other hybrid coordination networks when changing the bridging metal to Mn or the charge compensating anion to thiocyanate, i.e., for Mn(hmba) 3[MnBr4] and Co(hmba)3[Co(SCN)4] systems, respectively.