What Is The Crystal Structure Of Trisilver Triiodide?

Trisilver triiodide (Ag3I3) has a unique crystal structure called the β-AgI type. In this structure, each silver ion is surrounded by six iodine ions in a distorted octahedral arrangement, while each iodine ion is surrounded by three silver ions in a trigonal planar arrangement. The silver ions are located at the corners and center of the unit cell, while the iodine ions occupy the faces of the unit cell.

The β-AgI type structure belongs to the cubic system, with a space group of Pm-3m (No. 221). The lattice parameter is approximately 7.10 angstroms. The coordination number of each silver ion is six, while the coordination number of each iodine ion is three. The silver ions form three interpenetrating face-centered cubic lattices, while the iodine ions form a simple cubic lattice.

Trisilver triiodide is a semiconductor with a band gap of about 1.6 eV. It exhibits interesting optical and electrical properties due to its crystal structure and can be used in various optoelectronic applications such as solar cells, photodetectors, and light-emitting diodes.