A theoretical study of the linear and multiple approximation in a series of complexes formed by molecules with electron-rich hydrogen atoms has been carried out. The interaction energy (taking into account the zero-point energy and the basis set superposition error), the atomic charges, and the electron density of the monomers and complexes have been evaluated at the MP2/6-311++G** level. The linear complexes, which show a strong similarity to the standard hydrogen bonds except for the reverse direction of the electron transfer, could be defined as inverse hydrogen bonds.