“…Cuprous oxide (Cu 2 O) is a semiconducting compound. It crystallizes in cubic, hexagonal (CdI 2 -type), and tetragonal (CdCl 2 -type) structures at different pressures. − Under ambient conditions, Cu 2 O has the cubic structure. , It is widely used in thin-film transistors, optoelectronic, and nanoelectronic, spintronic, and photovoltaic applications. − Although there is progress, the nature of bonding in Cu 2 O is still not well understood . Initially, Cu 2 O was considered to be ionic, and partial occupancies in Cu-d,s,p shells were also suggested later. − The X-ray diffraction and convergent beam electron diffraction measurement combined with multipole refinement confirmed charge depletion from Cu-3d states on hybridization .…”