Sorry, but there is no chemical substance called Hg3Pb2. There might be a misunderstanding about the chemical notation here.
We can create compounds from mercury (Hg) and lead (Pb), but there is no specific compound with a ratio of 3:2 between these two elements based on the current chemical notation system.
To explain about a chemical substance, we need to know its exact structure, including the chemical elements and the ratio between them. For example, we can talk about HgS – cinnabar, which is a compound of mercury with sulfur, or PbCl2 – lead(II) chloride, which is a compound of lead with chlorine.