The relationship between linear elasticity theory of solids and their equations of state (EoS) is reviewed, along with the commonly-used types of isothermal EoS, thermal expansion models, and P-V-T EoS. A new console program, EosFit7c, is presented. It performs EoS calculations and fitting for both volume and linear isothermal data, isobaric data and P-T data. Linear data is handled by cubing the quantities and treating them as volumes in all EoS formulations. Least-squares fitting of EoS to data incorporates the option to weight the fit with the measurement uncertainties in P, V and T simultaneously. The EosFit7c program is built with a new library of subroutines for EoS calculations and manipulation, written in Fortran. The library has been incorporated as a module, cfml_eos, in the publicly-available CrysFML library. The module handles Murnaghan, Tait, Birch-Murnaghan, Vinet, and Natural Strain EoS. For P-V-T calculations any of these isothermal EoS can be combined with a variety of published thermal expansion models, including a model of thermal pressure. The entire library has been revalidated against other software and against an ab-initio re-derivation of the EoS, which identified a number of small errors in published formulae for some EoS.

EosFit7-GUI is a full graphical user interface designed to simplify the analysis of thermal expansion and equations of state (EoSs). The software allows users to easily perform least-squares fitting of EoS parameters to diffraction data collected as a function of varying pressure, temperature or both. It has been especially designed to allow rapid graphical evaluation of both parametric data and the EoS fitted to the data, making it useful both for data analysis and for teaching.

High-pressure x-ray diffraction studies on vaterite-type borates were reported on the above paper and their room-temperature P-V equation of state (EOS) determined. YBO3/Eu3+ and GdBO3 were found to have bulk moduli around 320 GPa, 90% larger than the bulk modulus obtained for EuBO3. Consequently, it was stated that vaterite-type borates are as incompressible as cubic BN. Such a different compressional behavior of isomorphic borates contradicts the known systematic of related borates. Here, we show that the conclusions reported on the above article could be hindered by experimental errors and artifacts. Ab initio calculations support our criticism giving similar bulk moduli (130–141 GPa) in the three compounds. Based upon these arguments, we conclude that the high-pressure behavior of vaterite-type borates should be revised using accurate experimental techniques. Finally, a methodological critic on EOS fits and to structural refinements is also presented.

ABSORB is a program to calculate and apply absorption corrections to singlecrystal X-ray intensity data from any source, any detector type and any instrument configuration. A new version, ABSORB-7, contains several significant new features. ABSORB-GUI has been developed to allow much easier specification of standard experiments and to enable experimental information to be imported from diffractometer software. The program that calculates the absorption calculations has been reconfigured to allow it to be called directly from other commercial and non-commercial software packages. In addition, a number of new features have been introduced to allow more flexibility in the way the experimental configuration is described and to correct synchrotron diffraction data collected with beams smaller than the sample crystal.

The high-pressure crystal structure evolution of CH3NH3PbBr3 (MAPbBr3) perovskite has been investigated by single-crystal X-ray diffraction and synchrotron-based powder X-ray diffraction. Single-crystal X-ray diffraction reveals that the crystal structure of MAPbBr3 undergoes two phase transitions following the space-group sequence: Pm3̅m → Im3̅ → Pmn21, unveiling the occurrence of a nonpolar/polar transition (Im3̅ → Pmn21). The transitions take place at around 0.8 and 1.8 GPa, respectively. This result contradicts the previously reported phase transition sequence: Pm3̅m → Im3̅ → Pnma . In this work, the crystal structures of each of the three phases are determined from single-crystal X-ray diffraction analysis, which is later supported by Rietveld refinement of powder X-ray diffraction patterns. The pressure dependence of the crystal lattice parameters and unit-cell volumes are determined from the two aforementioned techniques, as well as the bulk moduli for each phase. The bandgap behavior of MAPbBr3 has been studied up to around 4 GPa, by means of single-crystal optical absorption experiments. The evolution of the bandgap has been well explained using the pressure dependence of the Pb–Br bond distance and Pb–Br–Pb angles as determined from single-crystal X-ray diffraction experiments.

Resistively heated diamond-anvil cells have been used together with synchrotron x-ray diffraction to investigate the phase diagram of calcium up to 50 GPa and 800 K. The phase boundaries between the Ca-I (fcc), Ca-II (bcc), and Ca-III (simple cubic, sc) phases have been determined at these pressure-temperature conditions, and the ambient temperature equation of state has been generated. The equation of state parameters at ambient temperature have been determined from the experimental compression curve of the observed phases by using third-order Birch-Murnaghan and Vinet equations. A thermal equation of state was also determined for Ca-I and Ca-II by combining the room-temperature Birch-Murnaghan equation of state with a Berman-type thermal expansion model.

We report an ew family of titanium-organic frameworks that enlarges the limited number of crystalline,p orous materials available for this metal. They are chemically robust and can be prepared as single crystals at multi-gram scale from multiple precursors.T heir heterometallic structure enables engineering of their photoactivity by metal doping rather than by linker functionalization. Compared to other methodologies based on the post-synthetic metallation of MOFs,our approach is well-fitted for controlling the positioning of dopants at an atomic level to gain more precise control over the band-gap and electronic properties of the porous solid. Changes in the band-gap are also rationalized with computational modelling and experimentally confirmed by photocatalytic H 2 production.Metal-organic frameworks (MOFs) are crystalline,molecular solids built from the linking of organic and inorganic components with coordinative bonds.M OFs feature incomparable chemical diversity and sizeable three-dimensional porosity ideal for applications like gas storage,s eparation or catalysis. [1,2] However,t hey often suffer from poor chemical stability-particularly in humid conditions-limiting their performance and preventing large-scale application. [3] Chemically robust MOFs can be produced by using basic nitrogenated linkers [4,5] or highly charged metals like Zr or Hf IV , [6][7][8] for endowing the framework with stronger metal-linker bonds less prone to hydrolysis.Compared to these metals,t itanium is naturally more abundant and features advantageous properties like low toxicity,redox versatility and potential photocatalytic activity. However,t he synthesis of carboxylate-bridged Ti IV ,c rystalline,p orous materials remains still as ynthetic challenge. [9] This is arguably due to the high reactivity of Ti precursors, which are prone to hydrolysis in the solvothermal conditions conventional to MOF synthesis to form amorphous TiO 2 .As result, only af ew Ti IV -MOFs like MIL-125, [10] NTU-9 [11] and COK-69 [12] synthesised from simple Ti precursors or PCN-22 [13] and -by using preformed clusters-have been prepared by direct reaction with polycarboxylate linkers.Applications of Ti-MOFs in photocatalysis are continuously expanding due to the unique properties that can arise from the combination of high surface area, crystallinity good photostability and photoactivity. [15,16] Moreover,compared to traditional inorganic semiconductors like TiO 2 ,photocatalytic activity can be finely tuned by direct modification of the organic linker to enhance light absorption in the visible region. This can be attained by functionalization of the linker with substituents to shift light absorption as exemplified by NH 2 -MIL-125. [17][18][19] Still, other routes often used with oxide semiconductors remain underexplored. Here we present an ew family of chemically robust, photoactive titaniumorganic frameworks coined MUV-10 (MUV = Materials of Universidad de Va lencia), that can be prepared as single crystals at multi-gram scale.C ompared to other...

[see reaction]. The reaction of activated alkynes with carbonyl compounds in the presence of a catalytic amount of a nucleophile leads to enol-protected functionalized propargyl alcohols and 1,3-dioxolane compounds by way of a mild carbon-carbon bond formation reaction.