We have carried out a comprehensive study on the photoionization/fragmentation of Cr(CO)(6) by using the time-of-flight mass spectrometry (TOFMS) technique and a synchrotron radiation source in the photon energy range of similar to 8-40 eV. The appearance potentials (AP) of all the observed fragment ions were accurately determined, and those of some fragments, e.g., the doubly charged ions and the carbide fragments, were determined for the first time,The corresponding thermodynamic properties of these fragment ions have been derived. (C) 1997 American Institute of Physics.