We present ab initio results at the density functional theory level for the energetics and kinetics of H_2 and CH_4 in the SI clathrate hydrate. Our results complement a recent article by some of the authors [G. Roman-Perez et al., Phys. Rev. Lett. 1
05, 145901 (2010)] in that we show additional results of the energy landscape of H_2 and CH_4 in the various cages of the host material, as well as further results for energy barriers for all possible diffusion paths of H_2 and CH_4 through the water framework. We also report structural data of the low-pressure phase SI and the higher-pressure phases SII and SH.
We show that the Coulomb blockade in parallel dots pierced by magnetic flux $Phi$ completely blocks the resonant current for any value of $Phi$ except for integer multiples of the flux quantum $Phi_0$. This non-analytic (switching) dependence of the
current on $Phi$ arises only when the dot states that carry the current are of the same energy. The time needed to reach the steady state, however, diverges when $Phito nPhi_0$.
