# Diagonalisation of the g-matrix of low symmetry transition ions.
# Definition of an effective Hamiltonian and some soluble cases.
# [http://www.academia.edu/attachments/7689768/download_file The Use of Irreducible Operators for Determining the Complete set Set of linearly independent crystal field parametersLinearly Independent Crystal Field Parameters].# The main equations which define and an effective Hamiltonian.
# [http://cyt-ar.com.ar/cyt-ar/images/9/95/General_Theory_of_Effective_Hamiltonians.pdf General theory of Effective Hamiltonians].