Likelihood of a high-pressure phase of solid hydrogen involving termolecular complexes

R. LeSar, D. R. Herschbach
1981 The Journal of Physical Chemistry  
Electronic-structure calculations have shown that the six-center transition state for the concerted bond exchange among three hydrogen molecules lies -2 eV or more below the dissociation energy of the diatomic molecule. This suggests that solid hydrogen might undergo a high-pressure transition to form a new phase involving termolecular complexes. This possibility is examined by means of lattice-energy calculations employing semitheoretical pair potentials. Although uncertainties in the pair
more » ... ntials prevent a definite conclusion, the results obtained for a range of potentials indicate that a phase comprising a "largely dissociated" form of the six-center transition state may be stable at pressures above a few hundred kilobars. This complex would exist only because repulsive forces from the neighboring units in the crystal environment prevent its dissociation. (3) (a) For the CuCl reaction, see G.
doi:10.1021/j150625a016 fatcat:byjgwskhdnbmxlhb5ynylp3myq