In this video we will discuss in a mathematically non-rigorous manner the basics of crystal field theory and it application to molecules contain in Oh and Td symmetries. This will be followed by a video describing lower-symmetries. For those who wish to have a more mathematically rigorous presentation I would recommend the following texts: 1) "Ligand-Field Theory and its Applications" by Figgis and Hitchman 2) "Introduction to Ligand Field Theory" by Ballhausen Please note: barycentre is misspelled in the video-slides.