Equipotential surfaces such as one encounters in valence problems and particularly in the calculation of absolute rates, are discussed in a ``bond space'' instead of configuration space, with much simplification resulting both in the general aspects and in the practical handling of such problems. The exchange part, as well as the so-called coulombic part, of the bond energies is seen to obey a simple vector addition rule. A complete treatment of a four-atom reaction without symmetry (H2+ICl→HI+HCl) is carried out and results are compared with the existing experiments.