Effective Hamiltonians from Spin-Adapted Configuration Interaction.

A generalized extraction procedure for magnetic interactions using effective Hamiltonians is presented that is applicable to systems with more than two sites featuring local spins ≥ 1. To this end, closed, nonrecursive expressions pertaining to chains of arbitrary equal spins are derived with the graphical method of angular momentum. The method is illustrated by extracting magnetic couplings from ab initio calculations on a [CaMnO] cubane.

Spin-Orbit-Lattice Entangled State in A_{2}MgReO_{6} (A=Ca, Sr, Ba) Revealed by Resonant Inelastic X-Ray Scattering.

The 5d^{1} ordered double perovskites present an exotic playground for studying novel multipolar physics due to large spin-orbit coupling. We present Re L_{3} edge resonant inelastic x-ray scattering (RIXS) results that reveal the presence of the dynamic Jahn-Teller effect in the A_{2}MgReO_{6} (A=Ca, Sr, Ba) family of 5d^{1} double perovskites. The spin-orbit excitations in these materials show a strongly asymmetric line shape and exhibit substantial temperature dependence, indicating that they are dressed with lattice vibrations.

Raman study of decomposition of Na-bearing carbonates in water fluid at high P-T parameters.

The study of Na-carbonates stability and their transformations in aqueous carbonate fluid under high P-T conditions is relevant from the point of view of the understanding geochemical processes of the Na-assisted carbon circulation in the Earth's crust and subduction zones. In situ Raman study of Na-bearing carbonate-water-Fe-metal system in diamond anvil cell (DAC) at high P-T conditions revealed that carbonates decompose with abiogenic formation of formates and other organic compounds that differs from behavior of carbonates in dry system. XRD and FTIR methods have been used additionally to determine the phase composition.

A comparative study of the effect of high-pressure and low temperature on the crystal structure of lithium xanthinate hydrate.

The crystal structure of lithium xanthinate hydrate was studied by single crystal X-ray diffraction and Raman spectroscopy on cooling to 100 K and under compression to 5.3 GPa. A phase transition at ∼4 GPa is observed.