Reply to 'Comment on 'Increase in specific heat and possible hindered rotation of interstitial C2 molecules in neutron-irradiated graphite''

In a recent paper [T. Iwata and M. Watanabe, Phys. Rev. B 81, 014105 (2010)], we have interpreted the irradiation-induced increase in the low-temperature specific heat of neutron-irradiated graphite as due to the hindered rotation of interstitial C2 molecules with a rotational frequency of 1.39x1012 s-1 in the periodic potential with a height of 0.040 eV, and concluded that the C2 molecules do not form covalent bonds with atoms in the adjacent graphite layers. In their Comment [preceding paper, C. D. Latham et al., Phys. Rev. B 82, 056101 (2010)] on this paper, based on the recent first-principles theoretical calculations and related experiments, Latham et al. assert that self-interstitial atoms cannot exist as clusters of nearly free C2 molecules. In this Reply, based on the experiments, we address the issues raised by Latham et al. in their Comment.