A square-shaped complex with an electron-acceptor ligand: unique cubic crystal symmetry and similarity to the inorganic mineral katoite

We successfully obtained a Pt square complex having an electron-accepting ligand, which shows a strong similarity to the high-pressure phase of the natural mineral katoite in the solid state.

Phonons, phase transitions and thermal expansion in LiAlO2: an ab initio density functional study

We have used the ab initio density functional theory technique to understand the phase transitions and structural changes in various high temperature/pressure phases of LiAlO₂. The electronic band structure as well as phonon spectra is calculated for various phases as a function of pressure. The phonon entropy used for the calculations of Gibbs free energy is found to play an important role in the phase stability and phase transitions among various phases. A sudden increase in the polyhedral bond lengths (Li/Al-O) signifies the change from the tetrahedral to octahedral geometry at high-pressure phase transitions. The activation energy barrier for the high-pressure phase transitions is calculated. The phonon modes responsible for the phase transition (upon heating) from high pressure phases to ambient pressure phases are identified. Moreover, ab initio lattice dynamics calculations in the framework of quasi-harmonic approximations are used to study the anisotropic thermal expansion behavior of γ-LiAlO₂.

Assessing thermochemical properties of materials through ab initio quantum-mechanical methods: the case of α-Al2O3

Accurate ab initio calculations of thermodynamic and structural thermal properties of corundum demonstrate its quasi-harmonic nature up to the melting temperature.