A study of the influence of isotopic substitution on the melting point and temperature of maximum density of water by means of path integral simulations of rigid models

作者：McBride Carl; Aragones Juan L; Noya Eva G; Vega Carlos^*

来源：Physical Chemistry Chemical Physics, 2012, 14(43): 15199-15205.

DOI：10.1039/c2cp42393f

The melting point of ice I-h, as well as the temperature of maximum density (TMD) in the liquid phase, has been computed using the path integral Monte Carlo method. Two new models are introduced, TIP4PQ_D2O and TIP4PQ_T2O, which are specifically designed to study D2O and T2O respectively. We have also used these models to study the %26quot;competing quantum effects%26quot; proposal of Habershon, Markland and Manolopoulos; the TIP4PQ/2005, TIP4PQ/2005 (D2O) and TIP4PQ/2005 (T2O) models are able to study the isotopic substitution of hydrogen for deuterium or tritium whilst constraining the geometry, while the TIP4PQ_D2O and TIP4PQ_T2O models, where the O-H bond lengths are progressively shortened, permit the study of the influence of geometry (and thus dipole moment) on the isotopic effects. For TIP4PQ_D2O-TIP4PQ/2005 we found a melting point shift of 4.9 K (experimentally the value is 3.68 K) and a TMD shift of 6 K (experimentally 7.2 K). For TIP4PQ_T2O-TIP4PQ/2005 we found a melting point shift of 5.2 K (experimentally the value is 4.49 K) and a TMD shift of 7 K (experimentally 9.4 K).

• 出版日期2012