XYZ File Format
The XYZ format is a chemical file format. There is no formal standard and several variations exist, but a common XYZ format specifies the atomic structure geometry by giving the number of atoms with Cartesian coordinates that will be read on the first line, a comment on the second, and the lines of atomic coordinates in the following lines. The file format is used in molecular dynamics (MD) software for importing and exporting geometries. The units are generally in angstroms. Some variations include using atomic numbers instead of atomic symbols, or skipping the comment line. Files using the XYZ format conventionally have the .xyz extension. Technically, simplified diagram of atom records in the XYZ format depicted in below figure.
As mentioned before, the described XYZ files may be viewed using one of several free and open source softwares, including Jmol, Pymol, VMD, and Rasmol. Other non-free, shareware programs include ICM-Browser, MDL Chime, UCSF Chimera, StarBiochem (a Java-based interactive molecular viewer with integrated search of protein databank), Sirius, and VisProt3DS (a tool for Protein Visualization in 3D stereoscopic view in anaglyth and other modes), and Discovery Studio.