  In the framework of a quasi-molecular approach, the formation of hydrogen
atom in the pre-recombination period of evolution of the universe is analysed
quantitatively. Calculations in an adiabatic multi-level representation enable
estimates of probabilities of radiative transitions. The quasi-molecular
mechanism of recombination allows the formation of hydrogen molecular ion,
$H_2^+$, in its ground state. The probability of this process is comparable
with the probability of the creation of atomic hydrogen. The participation of a
second proton in the recombination increases the binding energy of an electron
and decreases the rate of recombination of hydrogen.
