A novel highpressure monoclinic metallic phase of V_{2}O_{3}
Y. Ding, C.C. Chen, Q. Zeng, H.S. Kim, M. J. Han, M. Balasubramanian, R. Gordon, F. Li, L. Bai, D. Popov, S. M. Heald, T. Gog, H. Mao, and M. van Veenendaal, Phys. Rev. Lett. 112, 056401 (2014); Editor’s Selection.
Vanadium sesquioxide, V_{2}O_{3}, is a prototypical metaltoinsulator system where, in temperaturedependent studies, the transition always coincides with a corundumtomonoclinic structural transition. As a function of pressure, V_{2}O_{3} follows the expected behavior of increased metallicity due to a larger bandwidth for pressures up to 12.5 GPa. Surprisingly, for higher pressures when the structure becomes
unstable, the resistance starts to increase. Around 32.5 GPa at 300 K, we observe a novel pressureinduced corundumtomonoclinic transition between two metallic phases, showing that the structural phase transition can be decoupled from the metalinsulator transition. Using xray Raman scattering, we find that screening effects, which are strong in the corundum phase, become weakened at high pressures. Theoretical calculations indicate that this can be related to a decrease in coherent quasiparticle strength, suggesting that the highpressure phase is likely a critical correlated metal, on the verge of Mottinsulating behavior

Momentumdependenced in Kedge resonant inelastic Xray scattering and its application to screening dynamics in CEphase La_{0.5}Sr_{1.5}LaNiO_{4}
T. F. Seman, X. Liu, J. P. Hill, M. van Veenendaal, and K. H. Ahn, Phys. Rev. B. 90, 045111 (2014).
We present a formula for the calculation of Kedge resonant inelastic xray scattering on transitionmetal compounds, based on a local interaction between the valence shell electrons and the 1s core hole. Extending a previous result, we include explicit momentum dependence and a basis with multiple corehole sites. We apply
this formula to a singlelayered charge, orbital, and spinordered manganite, La_{0.5}Sr_{1.5}MnO_{4}, and obtain good agreement with experimental data, in particular with regards to the large variation of the intensity with momentum. We find that the screening in La_{0.5}Sr_{1.5}MnO_{4} is highly localized around the corehole site and demonstrate the potential of Kedge resonant inelastic xray scattering as a probe of screening dynamics in materials. 
Smallangle scattering data analysis in GSASII
R. B. Von Dreele, J. Appl. Crystallography 47, 1784 (2014).
The General Structure Analysis System II (GSASII) now contains modules for the analysis of smallangle Xray scattering data. This includes processing of twodimensional images to create corrected onedimensional patterns, analysis via maximum entropy or total nonnegative leastsquares methods of the size distribution, assuming polydispersity, in the dilute limit, and modeling of the onedimensional data with combinations of Guinier/Porod, Porod, both dilute andcondensedpopulationsofscatteringobjects,andBraggscattering components; slit smearing corrections can be applied where needed. GSASII can apply these modeling tools over a sequence of data collected while some experimental condition is varied. This sequential refinement result can then be subjected to a post refinement analysis to determine global parameters encompassing the entire experiment. 