ABSTRACT
H2 is the simplest molecule, yet a proper understanding of its
properties requires the application of all the principles of quantum
mechanics. The chemical bond between two hydrogen atoms is
determined by the electronic wavefunction, which, in its ground
state, is characterized by zero electronic spin. The total energy of the
H2 molecule as a function of nuclear separation is shown in Fig. 6.1.
This potential energy curve has a minimum for a separation 0 = 0.741 A˚ and a well depth U0/kB = 55, 090 K. The nuclear degrees of freedom of the H2 molecule are conveniently separated into the
center-of-mass coordinates and the relative coordinate along of the
axis joining the two atoms.
