It is shown that the slope of the repulsive part of the interaction potential between hydrogen atoms above the dissociation limit decreases with decreasing internuclear separation. Such a form of the repulsive potential explains the reduction of the shock and quasi-isentropic compression curve slopes of hydrogen isotopes at megabar pressures obtained in recent experiments [R. F. Trunin, V. D. Urlin, and A. B. Medvedev, Phys.-Usp. \textbf{ 53}, 577 (2010), R. I. Ilkaev, \textit{ et al.}, AIP Conf. Proc. \textbf{ 706}, 73 (2004)].
Categories: physics.chem-ph physics.atom-ph