Welcome to ChemCoord’s documentation!


  • You can use it as a python module.
  • It reliably converts from Cartesian space (xyz-files) to internal coordinates (zmat-files) without introducing dummy atoms. Even in the case of linearity.
  • The created zmatrix is not only a transformation to internal coordinates, it is a “chemical” zmatrix. By chemical I mean, that e.g. distances are along bonds or dihedrals are defined as you draw them in chemical textbooks.
  • It derived from my own work and I heavily use it during the day. So all functions are tested and tailored around the workflow in theoretical chemistry.
  • The classes are safe to inherit from and you can easily costumize it for the needs of your project.