Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum path integral simulation of isotope effects in the melting
  temperature of ice Ih   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.

7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat