Any structure for which the enthalpy of formation lies on the convex hull is by definition thermodynamically stable and - in principle - can be synthesized experimentally53,54. References 1. Kaesz, H. D. & Saillant, R. B. Hydride complexes of the transition metals. Chem. Rev. 72, 231–...
First the pressure dependence of excess functions such as the excess Gibbs energy G8, the excess enthalpy H8, the excess entropy S8 and the excess heat capacity c. 8 is discussed. It can be obtained from the knowledge of the excess volume V8 as a function of pressure, temperature and ...
(PM, green) to non-magnetic (NM, cyan). The calculated magnetic moments of Fe and Co, and the total magnetic moment are also shown.bPhase diagram under hydrostatic decompression.cPhase diagram under non-hydrostatic compression.dPhase diagram under non-hydrostatic decompression. All diagrams are ...
The high-pressure behavior were explored by merging the evolutionary algorithm and ab initio total energy calculations, as implemented in the USPEX code. Enthalpy and electronic structure calculation were carried out by using the Vienna ab initio Simulation Package within the framework of GGA (Perdew–...
The latter are defined as those compounds for which any possible decomposition reaction is accompanied by a free energy (which at T = 0 K reduces to enthalpy) increase. In most cases, binary phase diagrams are targeted, for the large number of possible stoichiometries in a ternary...
The cutoff energy for the expan- sion of the wavefunction into plane waves was set at 400 eV and fine Monkhorst–Pack (MP) k meshes of 0.025 Å−1 have been chosen to ensure that all the enthalpy calculations are well converged. The phonon calculations have been carried out by ...
compounds with and without insertion of He atoms under pressures from 0 to 300 GPa. Then, the enthalpy change for the inclusion of He in these compounds is calculated in the same pressure range. The enthalpy differences for the reaction A-B + He → A-BHe were calculated as follows...
4. It is noteworthy that the M phase, although it has higher volume at low pressures, is more stable than the NM one, due to the magnetic interactions which result in a (slightly) lower enthalpy up to well above Pc. Moreover, both phases exhibit a T to CT transformation at the same...
it is believed that such an increase in the temperature occurs due to several factors including conversion of enthalpy of the stored gas in the high pressure storage tank to internal energy in
The compression ratio (e.g., P1/P2) in the compressor 1 being equal to the expansion ratio in the turbine 3, and the enthalpy of the gas entering the turbine being lower than the enthalpy of the gas exiting the compressor, the work W2 generated by the turbine 3 is smaller than the ...