Related Experiment Video
Updated: Jul 12, 2026
06:37
Analyzing Melts and Fluids from Ab Initio Molecular Dynamics Simulations with the UMD Package
Published on: September 17, 2021
Solid phase thermodynamic perturbation theory: test and application to multiple solid phases.
1School of Physics Science and Technology, Central South University, Changsha, Hunan 410083, People's Republic of China. chixiayzsq@yahoo.com
The Journal of Chemical Physics
|September 4, 2007
Summary
A new method accurately predicts hard sphere (HS) solid phase radial distribution functions (rdf) and thermodynamic properties. This approach reveals that short-ranged potentials can induce multiple solid phases and transitions, including triple points.
Area of Science:
- Thermodynamics
- Statistical Mechanics
- Materials Science
Background:
- Accurate prediction of solid phase properties is crucial for understanding material behavior.
- Existing methods for hard sphere (HS) solid phase radial distribution functions (rdf) have limitations.
Purpose of the Study:
- To develop a simple yet physically grounded procedure for determining HS solid phase rdf.
- To extend this procedure to various crystal structures beyond face-centered cubic (fcc).
- To investigate the induction of multiple solid phases and transitions using thermodynamic perturbation theory (TPT).
Main Methods:
- Proposed a novel procedure for calculating HS solid phase rdf.
- Validated the procedure by comparing predicted rdf with simulation data.
- Employed first-order TPT, utilizing HS solid phase rdf, to predict Helmholtz free energy and phase transitions.
Main Results:
- The proposed HS solid phase rdf procedure accurately predicts simulation data.
- First-order TPT successfully predicted isostructural fcc-fcc transitions in a hard core attractive Yukawa fluid, outperforming density functional perturbation theory.
- Short-ranged potentials were found to be sufficient for inducing multiple solid phases (fcc, bcc, sc) and transitions, including triple points.
Conclusions:
- The developed procedure offers a reliable method for calculating HS solid phase rdf.
- The study demonstrates the capability of first-order TPT in predicting complex phase behavior.
- Short-range interactions play a significant role in stabilizing diverse solid phases and driving transitions.
Related Concept Videos
01:20The Phase Rule
The phase rule describes the relationship between the variance (degrees of freedom), the number of components, and the number of phases in a system at equilibrium.Variance is a concept that denotes the number of independent intensive properties (properties are those that do not depend on the amount of material in the system), such as temperature, pressure, and composition, that can be altered without impacting the number of phases in equilibrium.In a single-component system, such as pure water,...
01:24Solid–Solid Solutions
The temperature-composition phase diagram of two solids, A and B, which are immiscible in the solid phase but form miscible liquids, shows that when the temperature is low, these two exist as separate, pure solids (A and B). As the temperature increases, they transition into a single-phase liquid solution where A and B coexist. Moving from point a1 to a2 in the phase diagram, the composition changes such that solid B begins to separate from the solution, enriching the remaining liquid with A.
02:31Phase Transitions
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to occupy...
01:21Phase Transitions
A phase transition is the process in which a substance changes from one state of matter to another, like from a solid to a liquid, liquid to gas, or vice versa, at a specific temperature and under given pressure conditions. This change is spontaneous and is affected by alterations in temperature and pressure. These parameters impact the strength of the forces between molecules (intermolecular forces) in the substance.During a phase transition, both the initial and final phases of the substance...
01:24Phase Diagram
A phase diagram is a graphical representation of the physical states of a substance under different conditions of temperature and pressure. It shows the boundaries between solid, liquid, and gas phases and the conditions at which these phases coexist in equilibrium. An area in a phase diagram represents a single phase, whereas lines or phase boundaries represent the equilibrium between two phases.In the phase diagram of water, the boundary line between the solid and liquid states illustrates...
01:19Phase Diagram
The phase of a given substance depends on the pressure and temperature. Thus, plots of pressure versus temperature showing the phase in each region provide considerable insights into the thermal properties of substances. Such plots are known as phase diagrams. For instance, in the phase diagram for water (Figure 1), the solid curve boundaries between the phases indicate phase transitions (i.e., temperatures and pressures at which the phases coexist).