This study investigates how chemical bonding can be tailored to design unconventional glasses, which differ significantly in short-range order and optical properties from their crystalline counterparts. Using quantum-chemical bonding descriptors, such as the number of electrons transferred and shared between adjacent atoms, the researchers compare the bonding in various glasses and their corresponding crystals. For common glasses like SiO₂, GeSe₂, and GeSe, the bonding in the glass and crystal is nearly identical, explaining their similar short-range order. However, unconventional glasses, such as those composed of GeTe, Sb₂Te₃, and GeSb₂Te₄, exhibit distinct bonding characteristics, indicating a different atomic arrangement and optical properties. These unconventional glasses are formed from crystals that employ metavalent bonding, a unique bonding mechanism involving a balance between ionic and covalent characteristics. The study shows that by identifying such crystals, it is possible to design unconventional glasses with distinct opto-electronic properties. The findings challenge Zachariasen's conjecture that the short-range order in glasses is similar to that in crystals, as they demonstrate that significant differences in bonding can lead to distinct properties in glasses. The research highlights the importance of chemical bonding in determining the properties of glasses and provides a framework for designing new materials with tailored properties. The study also emphasizes the role of quantum-chemical tools in analyzing and predicting the behavior of materials, offering insights into the design of functional glasses and other quantum materials.This study investigates how chemical bonding can be tailored to design unconventional glasses, which differ significantly in short-range order and optical properties from their crystalline counterparts. Using quantum-chemical bonding descriptors, such as the number of electrons transferred and shared between adjacent atoms, the researchers compare the bonding in various glasses and their corresponding crystals. For common glasses like SiO₂, GeSe₂, and GeSe, the bonding in the glass and crystal is nearly identical, explaining their similar short-range order. However, unconventional glasses, such as those composed of GeTe, Sb₂Te₃, and GeSb₂Te₄, exhibit distinct bonding characteristics, indicating a different atomic arrangement and optical properties. These unconventional glasses are formed from crystals that employ metavalent bonding, a unique bonding mechanism involving a balance between ionic and covalent characteristics. The study shows that by identifying such crystals, it is possible to design unconventional glasses with distinct opto-electronic properties. The findings challenge Zachariasen's conjecture that the short-range order in glasses is similar to that in crystals, as they demonstrate that significant differences in bonding can lead to distinct properties in glasses. The research highlights the importance of chemical bonding in determining the properties of glasses and provides a framework for designing new materials with tailored properties. The study also emphasizes the role of quantum-chemical tools in analyzing and predicting the behavior of materials, offering insights into the design of functional glasses and other quantum materials.