(*--------------------------------------------------------------------------- *) (* Coefficients of the HTSE *) (* for the dimerised and frustrated S=1/2 chain *) (*--------------------------------------------------------------------------- *) (* (Phys. Rev. B, Vol. 64, 024428 (2001)) *) (**) (* Alexander Buehler, Ute Loew and Goetz S. Uhrig *) (**) (**) (**) (* University of Cologne *) (* Institute for Theoretical Physics *) (* February 2001 *) (**) (**) (**) (* Mathematica version *) (* ------------------- *) (**) (* Read this file in Mathematica with: <