Methane clathrate: CH4 quantum rotor state dependent rattling potential
نویسندگان
چکیده
منابع مشابه
Equation of state of a model methane clathrate cage.
We investigate the behavior of a model methane clathrate cage under high hydrostatic pressures. The methane clathrate cage consists of 20 water molecules forming 12 pentagonal faces, with a methane molecule positioned at the cage center. The clathrate compound is located inside a fullerene-type arrangement of 180 He atoms to simulate an isotropic pressure. Different pressures are simulated by d...
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In addition to their ground state, diamond structure, Si, Ge and Sn can form crystalline solids called clathrates. As in the diamond structure, in the clathrates, the Group IV atoms are tetrahedrally coordinated and sp covalently bonded to their neighbors. However, the clathrates contain pentagonal atomic rings and have open-framework lattices containing 20-, 24and 28-atom ‘‘cages’’. There are ...
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Atomic motion of guest atoms inside semiconducting clathrate cages is considered an important source for glasslike thermal behavior. 69Ga and 71Ga nuclear magnetic resonance studies on type I Ba8Ga16Sn30 show a clear low-temperature relaxation peak attributed to the influence of Ba rattling dynamics on the framework-atom resonance, with a quadrupolar relaxation mechanism as the leading contribu...
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We have studied the vibrational properties of some of the compounds based on the Type II silicon, germanium, and tin-based clathrate materials using LDA electronic structure methods. The lattices in these framework materials have open cages which can contain weakly bound guest impurities, and these guests produce local (“rattling”) vibrational modes. Such modes may scatter the extended, heat ca...
متن کاملComparison of quantum dynamics and quantum transition state theory estimates of the H + CH4 reaction rate.
Thermal rate constants are calculated for the H + CH(4) --> CH(3) + H(2) reaction employing the potential energy surface of Espinosa-Garcia (Espinosa-Garcia, J. J. Chem. Phys. 2002, 116, 10664). Two theoretical approaches are used. First, we employ the multiconfigurational time-dependent Hartree method combined with flux correlation functions. In this way rate constants in the range 225-400 K a...
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ژورنال
عنوان ژورنال: The Journal of Chemical Physics
سال: 2006
ISSN: 0021-9606,1089-7690
DOI: 10.1063/1.2400031