Orthorhombic distortion on Li intercalation in anatase

Published versio

Monte Carlo calculations of the free energy of ice-like structures using the self-referential method

The self-referential method is a recently developed technique to compute the free energy of molecular crystals. In this paper, the method is extended to systems composed of nonlinear rigid molecules and applied to obtain the Helmholtz free energy of ice VII, hexagonal ice, cubic ice, and the Gibbs free energy of the empty structure I (sI) clathrate hydrate and fully occupied methane sI. It is shown that the method provides a viable alternative to other techniques to determine the free energy of solids. Good agreement with available reference literature data is found. We expect that the technique can be applied to a wide range of molecular crystals

Monte Carlo calculations of the free energy of binary SII hydrogen clathrate hydrates for identifying efficient promoter molecules

The thermodynamics of binary sII hydrogen clathrates with secondary guest molecules is studied with Monte Carlo simulations. The small cages of the sII unit cell are occupied by one H2 guest molecule. Different promoter molecules entrapped in the large cages are considered. Simulations are conducted at a pressure of 1000 atm in a temperature range of 233?293 K. To determine the stabilizing effect of different promoter molecules on the clathrate, the Gibbs free energy of fully and partially occupied sII hydrogen clathrates are calculated. Our aim is to predict what would be an efficient promoter molecule using properties such as size, dipole moment, and hydrogen bonding capability. The gas clathrate configurational and free energies are compared. The entropy makes a considerable contribution to the free energy and should be taken into account in determining stability conditions of binary sII hydrogen clathrates

Monte Carlo Calculations of the Free Energy of Binary SII Hydrogen Clathrate Hydrates for Identifying Efficient Promoter Molecules

The thermodynamics of binary sII hydrogen clathrates with secondary guest molecules is studied with Monte Carlo simulations. The small cages of the sII unit cell are occupied by one H₂ guest molecule. Different promoter molecules entrapped in the large cages are considered. Simulations are conducted at a pressure of 1000 atm in a temperature range of 233–293 K. To determine the stabilizing effect of different promoter molecules on the clathrate, the Gibbs free energy of fully and partially occupied sII hydrogen clathrates are calculated. Our aim is to predict what would be an efficient promoter molecule using properties such as size, dipole moment, and hydrogen bonding capability. The gas clathrate configurational and free energies are compared. The entropy makes a considerable contribution to the free energy and should be taken into account in determining stability conditions of binary sII hydrogen clathrates

Free Energy Calculations for Identifying Efficient Promoter Molecules of Binary sH Hydrogen Clathrates

To determine the stabilizing effect of different promoter molecules on the clathrate, the Gibbs free energy of fully occupied binary sH hydrogen clathrates with secondary guest molecules in the large cages is calculated with Monte Carlo simulations. The small and medium cages of sH are occupied by one H₂ guest molecule. Various promoter molecules enclathrated in the large cages are considered. Simulations are conducted in the pressure range of 250–1000 atm for temperatures ranging from 233 to 273 K. We investigate the effect of dipole moment and molecular size on the thermodynamic stability of sH hydrogen clathrate hydrate