Phase separation in H2O:N2 mixture: molecular dynamics simulations using atomistic force fields

Amitesh Maiti; Richard H Gee; Sorin Bastea; Laurence E Fried

doi:10.1063/1.2431171

Phase separation in H2O:N2 mixture: molecular dynamics simulations using atomistic force fields

J Chem Phys. 2007 Jan 28;126(4):044510. doi: 10.1063/1.2431171.

Authors

Amitesh Maiti¹, Richard H Gee, Sorin Bastea, Laurence E Fried

Affiliation

¹ Lawrence Livermore National Laboratory, University of California, California 94551, USA. [email protected]

PMID: 17286490
DOI: 10.1063/1.2431171

Abstract

A class II atomistic force field with Lennard-Jones 6-9 nonbond interactions is used to investigate equations of state (EOS) for important high explosive detonation products N(2) and H(2)O in the temperature range of 700-2500 K and pressure range of 0.1-10 GPa. A standard sixth order parameter-mixing scheme is then employed to study a 2:1 (molar) H(2)O:N(2) mixture, to investigate, in particular, the possibility of phase separation under detonation conditions. The simulations demonstrate several important results, including (i) the accuracy of computed EOS for both N(2) and H(2)O over the entire range of temperature and pressure considered, (ii) accurate mixing-demixing phase boundary as compared to experimental data, and (iii) the departure of mixing free energy from that predicted by ideal mixing law. The results provide comparison and guidance to state-of-the-art chemical kinetic models.