1,288 research outputs found
Thermophysical properties of liquid carbon dioxide under shock compressions: Quantum molecular dynamic simulations
Quantum molecular dynamic simulations are introduced to study the dynamical,
electrical, and optical properties of carbon dioxide under dynamic
compressions. The principal Hugoniot derived from the calculated equation of
states is demonstrated to be well accordant with experimental results.
Molecular dissociation and recombination are investigated through pair
correlation functions, and decomposition of carbon dioxide is found to be
between 40 and 50 GPa along the Hugoniot, where nonmetal-metal transition is
observed. In addition, the optical properties of shock compressed carbon
dioxide are also theoretically predicted along the Hugoniot
The equation of state and nonmetal-metal transition of benzene under shock compression
We employ quantum molecular dynamic simulations to investigate the behavior
of benzene under shock conditions. The principal Hugoniot derived from the
equation of state is determined. We compare our firs-principles results with
available experimental data and provide predictions of chemical reactions for
shocked benzene. The decomposition of benzene is found under the pressure of 11
GPa. The nonmetal-metal transition, which is associated with the rapid C-H bond
breaking and the formation of atomic and molecular hydrogen, occurs under the
pressure around 50 GPa. Additionally, optical properties are also studied.Comment: 12 pages, 5 figure
Hugoniot of shocked liquid deuterium up to 300 GPa: Quantum molecular dynamic simulations
Quantum molecular dynamic (QMD) simulations are introduced to study the
thermophysical properties of liquid deuterium under shock compression. The
principal Hugoniot is determined from the equation of states, where
contributions from molecular dissociation and atomic ionization are also added
onto the QMD data. At pressures below 100 GPa, our results show that the local
maximum compression ratio of 4.5 can be achieved at 40 GPa, which is in good
agreement with magnetically driven flyer and convergent-explosive experiments;
At the pressure between 100 and 300 GPa, the compression ratio reaches a
maximum of 4.95, which agrees well with recent high power laser-driven
experiments. In addition, the nonmetal-metal transition and optical properties
are also discussed.Comment: 4.1 pages, 4 figure
Ab initio study of shock compressed oxygen
Quantum molecular dynamic simulations are introduced to study the shock
compressed oxygen. The principal Hugoniot points derived from the equation of
state agree well with the available experimental data. With the increase of
pressure, molecular dissociation is observed. Electron spin polarization
determines the electronic structure of the system under low pressure, while it
is suppressed around 30 50 GPa. Particularly, nonmetal-metal transition
is taken into account, which also occurs at about 30 50 GPa. In
addition, the optical properties of shock compressed oxygen are also discussed.Comment: 5 pages, 5 figure
Electrical and optical properties of fluid iron from compressed to expanded regime
Using quantum molecular dynamics simulations, we show that the electrical and
optical properties of fluid iron change drastically from compressed to expanded
regime. The simulation results reproduce the main trends of the electrical
resistivity along isochores and are found to be in good agreement with
experimental data. The transition of expanded fluid iron into a nonmetallic
state takes place close to the density at which the constant volume derivative
of the electrical resistivity on internal energy becomes negative. The study of
the optical conductivity, absorption coefficient, and Rosseland mean opacity
shows that, quantum molecular dynamics combined with the Kubo-Greenwood
formulation provides a powerful tool to calculate and benchmark the electrical
and optical properties of iron from expanded fluid to warm dense region
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