  The R--matrix method is implemented to study the heavy charm and bottom
diquark, triquark, tetraquark and pentaquarks in configuration space, as the
bound states of quark--antiquark, diquark--quark, diquark--antidiquark and
diquark--antitriquark systems, respectively. The mass spectrum and the size of
these systems are calculated for different partial wave channels. The
calculated masses are compared with recent theoretical results obtained by
other methods in momentum and configuration spaces and also by available
experimental data.
