The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Jerome Delhommelle - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of the grand-Canonical Partition Function using expanded Wang-Landau simulations. V. Impact of an electric field on the thermodynamic properties and ideality contours of water.
The Journal of chemical physics, 2016Co-Authors: Caroline Desgranges, Jerome DelhommelleAbstract:Using molecular simulation, we assess the impact of an electric field on the properties of water, modeled with the SPC/E potential, over a wide range of states and conditions. Electric fields of the order of 0.1 V/A and beyond are found to have a significant impact on the grand-Canonical Partition Function of water, resulting in shifts in the chemical potential at the vapor-liquid coexistence of up to 20%. This, in turn, leads to an increase in the critical temperatures by close to 7% for a field of 0.2 V/A, to lower vapor pressures, and to much larger entropies of vaporization (by up to 35%). We interpret these results in terms of the greater density change at the transition and of the increased structural order resulting from the applied field. The thermodynamics of compressed liquids and of supercritical water are also analyzed over a wide range of pressures, leading to the determination of the Zeno line and of the curve of ideal enthalpy that span the supercritical region of the phase diagram. Rescali...
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Evaluation of the grand-Canonical Partition Function using expanded Wang-Landau simulations. I. Thermodynamic properties in the bulk and at the liquid-vapor phase boundary
The Journal of chemical physics, 2012Co-Authors: Caroline Desgranges, Jerome DelhommelleAbstract:The Wang-Landau sampling is a powerful method that allows for a direct determination of the density of states. However, applications to the calculation of the thermodynamic properties of realistic fluids have been limited so far. By combining the Wang-Landau method with expanded grand-Canonical simulations, we obtain a high-accuracy estimate for the grand-Canonical Partition Function for atomic and molecular fluids. Then, using the formalism of statistical thermodynamics, we are able to calculate the thermodynamic properties of these systems, for a wide range of conditions spanning the single-phase regions as well as the vapor-liquid phase boundary. Excellent agreement with prior simulation work and with the available experimental data is obtained for argon and CO2, thereby establishing the accuracy of the method for the calculation of thermodynamic properties such as free energies and entropies.
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Evaluation of the grand-Canonical Partition Function using expanded Wang-Landau simulations. II. Adsorption of atomic and molecular fluids in a porous material.
The Journal of chemical physics, 2012Co-Authors: Caroline Desgranges, Jerome DelhommelleAbstract:We propose to apply expanded Wang-Landau simulations to study the adsorption of atomic and molecular fluids in porous materials. This approach relies on a uniform sampling of the number of atoms and molecules adsorbed. The method consists in determining a high-accuracy estimate of the grand-Canonical Partition Function for the adsorbed fluids. Then, using the formalism of statistical mechanics, we calculate absolute and excess thermodynamic properties relevant to adsorption processes. In this paper, we examine the adsorption of argon and carbon dioxide in the isoreticular metal-organic framework (IRMOF-1). We assess the reliability of the method by showing that the predicted adsorption isotherms and isosteric heats are in excellent agreement with simulation results obtained from grand-Canonical Monte Carlo simulations. We also show that the proposed method is very efficient since a single expanded Wang-Landau simulation run at a given temperature provides the whole adsorption isotherm. Moreover, this approach provides a direct access to a wide range of thermodynamic properties, such as, e.g., the excess Gibbs free energy and the excess entropy of adsorption.
Caroline Desgranges - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of the grand-Canonical Partition Function using expanded Wang-Landau simulations. V. Impact of an electric field on the thermodynamic properties and ideality contours of water.
The Journal of chemical physics, 2016Co-Authors: Caroline Desgranges, Jerome DelhommelleAbstract:Using molecular simulation, we assess the impact of an electric field on the properties of water, modeled with the SPC/E potential, over a wide range of states and conditions. Electric fields of the order of 0.1 V/A and beyond are found to have a significant impact on the grand-Canonical Partition Function of water, resulting in shifts in the chemical potential at the vapor-liquid coexistence of up to 20%. This, in turn, leads to an increase in the critical temperatures by close to 7% for a field of 0.2 V/A, to lower vapor pressures, and to much larger entropies of vaporization (by up to 35%). We interpret these results in terms of the greater density change at the transition and of the increased structural order resulting from the applied field. The thermodynamics of compressed liquids and of supercritical water are also analyzed over a wide range of pressures, leading to the determination of the Zeno line and of the curve of ideal enthalpy that span the supercritical region of the phase diagram. Rescali...
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Evaluation of the grand-Canonical Partition Function using expanded Wang-Landau simulations. I. Thermodynamic properties in the bulk and at the liquid-vapor phase boundary
The Journal of chemical physics, 2012Co-Authors: Caroline Desgranges, Jerome DelhommelleAbstract:The Wang-Landau sampling is a powerful method that allows for a direct determination of the density of states. However, applications to the calculation of the thermodynamic properties of realistic fluids have been limited so far. By combining the Wang-Landau method with expanded grand-Canonical simulations, we obtain a high-accuracy estimate for the grand-Canonical Partition Function for atomic and molecular fluids. Then, using the formalism of statistical thermodynamics, we are able to calculate the thermodynamic properties of these systems, for a wide range of conditions spanning the single-phase regions as well as the vapor-liquid phase boundary. Excellent agreement with prior simulation work and with the available experimental data is obtained for argon and CO2, thereby establishing the accuracy of the method for the calculation of thermodynamic properties such as free energies and entropies.
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Evaluation of the grand-Canonical Partition Function using expanded Wang-Landau simulations. II. Adsorption of atomic and molecular fluids in a porous material.
The Journal of chemical physics, 2012Co-Authors: Caroline Desgranges, Jerome DelhommelleAbstract:We propose to apply expanded Wang-Landau simulations to study the adsorption of atomic and molecular fluids in porous materials. This approach relies on a uniform sampling of the number of atoms and molecules adsorbed. The method consists in determining a high-accuracy estimate of the grand-Canonical Partition Function for the adsorbed fluids. Then, using the formalism of statistical mechanics, we calculate absolute and excess thermodynamic properties relevant to adsorption processes. In this paper, we examine the adsorption of argon and carbon dioxide in the isoreticular metal-organic framework (IRMOF-1). We assess the reliability of the method by showing that the predicted adsorption isotherms and isosteric heats are in excellent agreement with simulation results obtained from grand-Canonical Monte Carlo simulations. We also show that the proposed method is very efficient since a single expanded Wang-Landau simulation run at a given temperature provides the whole adsorption isotherm. Moreover, this approach provides a direct access to a wide range of thermodynamic properties, such as, e.g., the excess Gibbs free energy and the excess entropy of adsorption.
B. V. Costa - One of the best experts on this subject based on the ideXlab platform.
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using zeros of the Canonical Partition Function map to detect signatures of a berezinskii kosterlitz thouless transition
Computer Physics Communications, 2016Co-Authors: J. C. S. Rocha, L. A. S. Mól, B. V. CostaAbstract:Abstract Using the two dimensional X Y − ( S ( O ( 3 ) ) ) model as a test case, we show that analysis of the Fisher zeros of the Canonical Partition Function can provide signatures of a transition in the Berezinskii–Kosterlitz–Thouless ( B K T ) universality class. Studying the internal border of zeros in the complex temperature plane, we found a scenario in complete agreement with theoretical expectations which allow one to uniquely classify a phase transition as in the B K T class of universality. We obtain T BKT in excellent accordance with previous results. A careful analysis of the behavior of the zeros for both regions R e ( T ) ≤ T BKT and R e ( T ) > T BKT in the thermodynamic limit shows that I m ( T ) goes to zero in the former case and is finite in the last one.
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Using zeros of the Canonical Partition Function map to detect signatures of a Berezinskii–Kosterlitz–Thouless transition
Computer Physics Communications, 2016Co-Authors: J. C. S. Rocha, L. A. S. Mól, B. V. CostaAbstract:Abstract Using the two dimensional X Y − ( S ( O ( 3 ) ) ) model as a test case, we show that analysis of the Fisher zeros of the Canonical Partition Function can provide signatures of a transition in the Berezinskii–Kosterlitz–Thouless ( B K T ) universality class. Studying the internal border of zeros in the complex temperature plane, we found a scenario in complete agreement with theoretical expectations which allow one to uniquely classify a phase transition as in the B K T class of universality. We obtain T BKT in excellent accordance with previous results. A careful analysis of the behavior of the zeros for both regions R e ( T ) ≤ T BKT and R e ( T ) > T BKT in the thermodynamic limit shows that I m ( T ) goes to zero in the former case and is finite in the last one.
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Signatures of the Berezinskii-Kosterlitz-Thouless transition on the location of the zeros of the Canonical Partition Function for the 2D XY-model
arXiv: Statistical Mechanics, 2015Co-Authors: J. C. S. Rocha, L. A. S. Mól, B. V. CostaAbstract:In this work we show how one can use the zeros of the Canonical Partition Function, the Fisher zeros, to unambiguously characterize a transition as being in the Berezinskii-Kosterlitz-Thouless ($BKT$) class of universality. By studying the zeros map for the 2D XY-model, we found that its internal border coalesces into the real positive axis in a finite region corresponding to temperatures smaller than the $BKT$ transition temperature. This behavior is consistent with the predicted existence of a line of critical points below the transition temperature, allowing one to distinguish the $BKT$ class of universality from other possibilities.
Wu-sheng Dai - One of the best experts on this subject based on the ideXlab platform.
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Unified framework for generalized quantum statistics: Canonical Partition Function, maximum occupation number, and permutation phase of wave Function
arXiv: Statistical Mechanics, 2020Co-Authors: Chi-chun Zhou, Wu-sheng DaiAbstract:Beyond Bose and Fermi statistics, there still exist various kinds of generalized quantum statistics. Two ways to approach generalized quantum statistics: (1) in quantum mechanics, generalize the permutation symmetry of the wave Function and (2) in statistical mechanics, generalize the maximum occupation number of quantum statistics. The connection between these two approaches, however, is obscure. In this paper, we suggest a unified framework to describe various kinds of generalized quantum statistics. We first provide a general formula of Canonical Partition Functions of ideal $N$-particle gases obeying various kinds of generalized quantum statistics. Then we reveal the connection between the permutation phase of the wave Function and the maximum occupation number, through constructing a method to obtain the permutation phase and the maximum occupation number from the Canonical Partition Function. In our scheme, the permutation phase of wave Functions is generalized to a matrix phase, rather than a number. It is commonly accepted that different kinds of statistics are distinguished by the maximum number. We show that the maximum occupation number is not sufficient to distinguish different kinds of generalized quantum statistics. As examples, we discuss a series of generalized quantum statistics in the unified framework, giving the corresponding Canonical Partition Functions, maximum occupation numbers, and the permutation phase of wave Functions. Especially, we propose three new kinds of generalized quantum statistics which seem to be the missing pieces in the puzzle. The mathematical basis of the scheme are the mathematical theory of the invariant matrix, the Schur-Weyl duality, the symmetric Function, and the representation theory of the permutation group and the unitary group. The result in this paper builds a bridge between the statistical mechanics and such mathematical theories.
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Canonical Partition Functions: ideal quantum gases, interacting classical gases, and interacting quantum gases
Journal of Statistical Mechanics: Theory and Experiment, 2018Co-Authors: Chi-chun Zhou, Wu-sheng DaiAbstract:In statistical mechanics, for a system with fixed number of particles, e.g., a finite-size system, strictly speaking, the thermodynamic quantity needs to be calculated in the Canonical ensemble. Nevertheless, the calculation of the Canonical Partition Function is difficult.\textbf{ }In this paper, based on the mathematical theory of the symmetric Function, we suggest a method for the calculation of the Canonical Partition Function of\ ideal quantum gases, including ideal Bose, Fermi, and Gentile gases. Moreover, we express the Canonical Partition Functions of interacting classical and quantum gases given by the classical and quantum cluster expansion methods in terms of the Bell polynomial in mathematics. The virial coefficients of ideal Bose, Fermi, and Gentile gases is calculated from the exact Canonical Partition Function. The virial coefficients of interacting classical and quantum gases is calculated from the Canonical Partition Function by using the expansion of the Bell polynomial, rather than calculated from the grand Canonical potential.
J. C. S. Rocha - One of the best experts on this subject based on the ideXlab platform.
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using zeros of the Canonical Partition Function map to detect signatures of a berezinskii kosterlitz thouless transition
Computer Physics Communications, 2016Co-Authors: J. C. S. Rocha, L. A. S. Mól, B. V. CostaAbstract:Abstract Using the two dimensional X Y − ( S ( O ( 3 ) ) ) model as a test case, we show that analysis of the Fisher zeros of the Canonical Partition Function can provide signatures of a transition in the Berezinskii–Kosterlitz–Thouless ( B K T ) universality class. Studying the internal border of zeros in the complex temperature plane, we found a scenario in complete agreement with theoretical expectations which allow one to uniquely classify a phase transition as in the B K T class of universality. We obtain T BKT in excellent accordance with previous results. A careful analysis of the behavior of the zeros for both regions R e ( T ) ≤ T BKT and R e ( T ) > T BKT in the thermodynamic limit shows that I m ( T ) goes to zero in the former case and is finite in the last one.
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Using zeros of the Canonical Partition Function map to detect signatures of a Berezinskii–Kosterlitz–Thouless transition
Computer Physics Communications, 2016Co-Authors: J. C. S. Rocha, L. A. S. Mól, B. V. CostaAbstract:Abstract Using the two dimensional X Y − ( S ( O ( 3 ) ) ) model as a test case, we show that analysis of the Fisher zeros of the Canonical Partition Function can provide signatures of a transition in the Berezinskii–Kosterlitz–Thouless ( B K T ) universality class. Studying the internal border of zeros in the complex temperature plane, we found a scenario in complete agreement with theoretical expectations which allow one to uniquely classify a phase transition as in the B K T class of universality. We obtain T BKT in excellent accordance with previous results. A careful analysis of the behavior of the zeros for both regions R e ( T ) ≤ T BKT and R e ( T ) > T BKT in the thermodynamic limit shows that I m ( T ) goes to zero in the former case and is finite in the last one.
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Signatures of the Berezinskii-Kosterlitz-Thouless transition on the location of the zeros of the Canonical Partition Function for the 2D XY-model
arXiv: Statistical Mechanics, 2015Co-Authors: J. C. S. Rocha, L. A. S. Mól, B. V. CostaAbstract:In this work we show how one can use the zeros of the Canonical Partition Function, the Fisher zeros, to unambiguously characterize a transition as being in the Berezinskii-Kosterlitz-Thouless ($BKT$) class of universality. By studying the zeros map for the 2D XY-model, we found that its internal border coalesces into the real positive axis in a finite region corresponding to temperatures smaller than the $BKT$ transition temperature. This behavior is consistent with the predicted existence of a line of critical points below the transition temperature, allowing one to distinguish the $BKT$ class of universality from other possibilities.