  In this paper we present in greater detail previous work on the
Born-Oppenheimer approximation to treat the hydrogen bond of QCD, and add a
similar treatment of doubly heavy baryons. Doubly heavy exotic resonances X and
Z can be described as color molecules of two-quark lumps, the analogue of the
H_2 molecule, and doubly heavy baryons as the analog of the H_2^+ ion, except
that the two heavy quarks attract each other. We compare our results with
constituent quark model and lattice QCD calculations and find further evidence
in support of this upgraded picture of compact tetraquarks and baryons.
