Partial Molar Entropy and Partial Molar Heat Capacity of Electrons in Metals and Superconductors

There are at least two valid approaches to the thermodynamics of electrons in metals. One takes a microscopic view, based on models of electrons in metals and superconductor and uses statistical mechanics to calculate the total thermodynamic functions for the model-based system. Another uses partial molar quantities, which is a rigorous thermodynamic method to analyze systems with components that can cross phase boundaries and is particularly useful when applied to a system composed of interacting components. Partial molar quantities have not been widely used in the field of solid state physics. The present paper will explore the application of partial molar electronic entropy and partial molar electronic heat capacity to electrons in metals and superconductors. This provides information that is complementary information from other approaches to the thermodynamics of electrons in metals and superconductors and can provide additional insight into the properties of those materials. Furthermore, the application of partial molar quantities to electrons in metals and superconductors has direct relevance to long-standing problems in other fields, such as the thermodynamics of ions in solution and the thermodynamics of biological energy transformations. A unifying principle between reversible and irreversible thermodynamics is also discussed, including how this relates to the completeness of thermodynamic theory.

DFT Study on Some Properties of Polybrominated Phenoxathiin 10-Oxides

With the B3LYP calculation method of density functional theory（DFT）and the 6-31G＊ basis set,full optimization calculation was made for phenoxathiin10-oxide（PTO）and 135 polybromine phenoxathiin 10-oxides（PBPTOs）with the Gaussian 03 program and molar heat capacity in constant volume（CVθ）value of each molecule in the standard state was obtained.The relation between CVθ and the substitution position and number of bromine atom（NPBS）was studied,and the results indicated good correlation（R2 = 1.000）between CVθ and NPBS of PBPTO compounds.Based on the output file of Gaussian 03 program,molar heat capacity at constant pressure（Cp,m）of PBPTO compounds from 200 to 1,000 K was calculated with the statistical thermodynamics program,and the correlation equation between Cp,m and temperature（T,T-1 and T-2）was obtained with the least-squares method,and the correlation coefficient of the correlation equation（R2）was 1.000.In addition,based on the partition function of each molecule calculated by vibration analysis,the relative rate constant of formation of each molecule was calculated.

Studies of Thermodynamic Properties and Relative Stability of Polybrominated Xanthones by Density Functional Theory

The thermodynamic properties of xanthone（XTH） and 135 polybrominated xanthones（PBXTHs） in the standard state have been calculated at the B3LYP/6-31G＊ level using Gaussian 03 program.The isodesmic reactions were designed to calculate the standard enthalpy of formation（△fHθ） and standard free energy of formation（△fGθ） of PBXTH congeners.The relations of these thermodynamic parameters with the number and position of Br atom substitution（NPBS） were discussed,and it was found that there exist high correlation between thermodynamic parameters（entropy（Sθ）,△fHθ and △fGθ） and NPBS.According to the relative magnitude of their △fGθ,the relative stability order of PBXTH congeners was theoretically proposed.The relative rate constants of formation reactions of PBXTH congeners were calculated,Moreover,the values of molar heat capacity at constant pressure（Cp,m） from 200 to 1000 K for PBXTH congeners were also calculated,and the temperature dependence relation of them was obtained,suggesting very good relationships between Cp,m and temperature（T,T^1 and T^2） for almost all PBXTH congeners.