On another thread on this website it mentioned how it was possible to melt diamonds, but what would be the micro-level occur for that to happen. This question applies to Silicon Oxide aswell. They both have infinite structures. Which bonds would break or even weaken for them to transition states? For example, when a regular covalent solid is heated, the intermolecular forces of attraction weaken and the solid melts. How would that work for a structure like that of diamond?