Use Of Cartesian Coordinates
The molecular geometry can be given in terms of Cartesian coordinates (keyword COORD=CARTESIAN). The format is straightforward, as each line just contains the atomic symbol together with the values of the Cartesian coordinates in free format. The coordinates may be given in either atomic or Angström units (depending on the UNITS keyword with Angström as default; atomic units are invoked by the keyword UNITS=BOHR).
For example, for formaldehyde, a possible input in Cartesian Coordinates (in Angström) might be:
The use of Cartesian coordinates within CFOUR is of limited value, as so far only single-point calculations can be performed with this type of input.
It should be noted that via the file JMOLplot or MOLDEN (created by the module xjoda) a visualization of the geometry of the molecule is possible by using
JMOL (geometries) or MOLDEN (geometries, molecular orbitals, electron densities).