High-Pressure Effects on Hofmann-Type Clathrates: Promoted Release and Restricted Insertion of Guest Molecules.

The search for effective methods to accurately control host-guest relationship is the central theme of host-guest chemistry. In this work, high pressure successfully promotes guest release in the Hofmann-type clathrate of [Ni(NH)Ni(CN)]·2CH (Ni-Bz) and restricts guest insertion into Ni(NH)Ni(CN) (Ni-Ni). Because of the weak host-guest interactions of Ni-Bz, external force gradually removes guest benzene from the host framework, leading to puckered layers.

Ab initio structure determination of n-diamond.

A systematic computational study on the crystal structure of n-diamond has been performed using first-principle methods. A novel carbon allotrope with hexagonal symmetry R32 space group has been predicted. We name it as HR-carbon.

Ab initio investigation of CaO-ZnO alloys under high pressure.

Ca(x)Zn(1-x)O alloys are potential candidates to achieve wide band-gap, which might significantly promote the band gap engineering and heterojunction design. We performed a crystal structure search for CaO-ZnO system under pressure, using an ab initio evolutionary algorithm implemented in the USPEX code. Four stable ordered Ca(x)Zn(1-x)O structures are found in the pressure range of 8.

Structural, mechanical, and electronic properties of Rh2B and RhB2: first-principles calculations.

The crystal structures of Rh2B and RhB2 at ambient pressure were explored by using the evolutionary methodology. A monoclinic P2₁/m structure of Rh2B was predicted and donated as Rh2B-I, which is energetically much superior to the previously experimentally proposed Pnma structure. At the pressure of about 39 GPa, the P2₁/m phase of Rh2B transforms to the C2/m phases.

First-principles study on the structural and electronic properties of metallic HfH2 under pressure.

The crystal structures and properties of hafnium hydride under pressure are explored using the first-principles calculations based on density function theory. The material undergoes pressure-induced structural phase transition I4/mmm → Cmma → P21/m at 180 and 250 GPa, respectively, and all of these structures are metallic. The superconducting critical temperature Tc values of I4/mmm, Cmma, and P21/m are 47-193 mK, 5.

Miscibility and ordered structures of MgO-ZnO alloys under high pressure.

The MgxZn(1-x)O alloy system may provide an optically tunable family of wide band gap materials that can be used in various UV luminescences, absorption, lighting, and display applications. A systematic investigation of the MgO-ZnO system using ab initio evolutionary simulations shows that MgxZn(1-x)O alloys exist in ordered ground-state structures at pressures above about 6.5 GPa.

The CCAAT enhancer-binding protein alpha (C/EBPalpha) requires a SWI/SNF complex for proliferation arrest.

The transcription factor CCAAT enhancer-binding protein alpha (C/EBPalpha) is a tumor suppressor in myeloid cells and inhibits proliferation in all cell types examined. C/EBPalpha interacts with the SWI/SNF chromatin-remodeling complex during the regulation of differentiation-specific genes. Here we show that C/EBPalpha fails to suppress proliferation in SWI/SNF defective cell lines after knock-down of SWI/SNF core components or after deletion of the SWI/SNF interaction domain in C/EBPalpha, respectively.