Physics – Condensed Matter – Materials Science
Scientific paper
2011-08-18
J. Chem. Phys. 133, 144511 (2010)
Physics
Condensed Matter
Materials Science
14 pages, 13 figures, 5 tables
Scientific paper
10.1063/1.3503764
The isotope effect in the melting temperature of ice Ih has been studied by free energy calculations within the path integral formulation of statistical mechanics. Free energy differences between isotopes are related to the dependence of their kinetic energy on the isotope mass. The water simulations were performed by using the q-TIP4P/F model, a point charge empirical potential that includes molecular flexibility and anharmonicity in the OH stretch of the water molecule. The reported melting temperature at ambient pressure of this model (T = 251 K) increases by 6.5+-0.5 K and 8.2+-0.5 K upon isotopic substitution of hydrogen by deuterium and tritium, respectively. These temperature shifts are larger than the experimental ones (3.8 K and 4.5 K, respectively). In the classical limit, the melting temperature is nearly the same as that for tritiated ice. This unexpected behavior is rationalized by the coupling between intermolecular interactions and molecular flexibility. This coupling makes the kinetic energy of the OH stretching modes larger in the liquid than in the solid phase. However the opposite behavior is found for intramolecular modes, which display larger kinetic energy in ice than in liquid water.
Herrero Carlos P.
Ramirez Rafael
No associations
LandOfFree
Quantum path integral simulation of isotope effects in the melting temperature of ice Ih does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Quantum path integral simulation of isotope effects in the melting temperature of ice Ih, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quantum path integral simulation of isotope effects in the melting temperature of ice Ih will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-181240