The Pentaquarks in the Linear Molecular Heptaquark Model
  In this talk, multiquarks are studied microscopically in a standard quark model. In pure ground-state pentaquarks the short-range interaction is computed and it is shown to be repulsive. An additional quark-antiquark pair is then considered, and this is suggested to produce linear molecular system, with a narrow decay width. The quarks assemble in three hadronic clusters, and the central hadron provides stability. The possible crypto-heptaquark hadrons with exotic pentaquark flavours, with strange, charmed and bottomed quarks, are predicted. 
P. Bicudo