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The Structure of Solids
Published in Joseph Datsko, Materials Selection for Design and Manufacturing, 2020
A molecule is a group of atoms that are held together by strong ionic or covalent bonds. A molecular solid is a structure made up of molecules that are attracted to each other by the weak van der Waals forces. The two most common types of molecular solids are the silicates and the polymers. The silicates have ionic intramolecular bonds and the polymers have covalent ones. The polymers, which are more important in terms of mechanical properties in manufacturing, will be discussed in more detail.
Pseudo pair potential between protons in dense hydrogen from first principles
Published in Molecular Physics, 2022
Robbie S. Robinson, Praveer Tiwari, Jeffrey M. McMahon
Generation of the required MD candidate systems was first equilibrated using 2048 steps (in accordance with 1/4 the 820 energy configurations and step width of 10) with the Andersen thermostat set at 1133.7 K (chosen from the average temperature resulting from the ZPE of the DFT calculations) for relaxing the electronic wave function for the atomic-solid phase. The sampling and integration of the Brillouin-zones were implemented exactly as the DFT calculations. This was done for four evenly spaced density configurations defined by the Wigner–Seitz radius : , , , and using PWscf. The values in the computation were chosen to encompass the hypothetical [14] and somewhat expected [5,60] transition region from semi-metallic molecular solid phase to a monatomic metallic solid phase. The output atomic positions from the equilibration process were then fed into the generation process with 8192 steps. All other inputs remained consistent.
Synthesis, crystal structure, and optical properties of benzyl isoquinolinium dibromo-bis(isothiocyanate)zinc(II)
Published in Journal of Coordination Chemistry, 2022
Ke-Lai Chen, Yi-Lin Xu, Ke Yin, Yu Cai, Yan-Lin Chen, Yong-Zhen He, Jia-Yu Yu, Wen-Xu Zheng, Chun-Lin Ni
The emission spectra of the title compound and the corresponding intermediate [BzIQl]Br were all investigated in the solid state at room temperature. As shown in Figure 7, two main emission peaks at 394 and 467 nm are observed for [BzIQl]Br excited at 241 nm, due to aromatic functional groups with low energy π→π* transition levels [38]. At the same time, the title compound [BzIQl]2[Zn(NCS)2Br2] displays two main emission peaks at 388 and 466 nm. A smaller violet-shift of 6 nm of the maximum emission peak occurred when the intermediate [BzIQl]+ cation was combined with the self-assembly [Zn(NCS)2Br2]2− anion to form [BzIQl]2[Zn(NCS)2Br2] molecular solid, which is due to the C–H···Br hydrogen bonds between the [BzIQl]+ cation and [Zn(NCS)2Br2]2− anion.
Synthesis, structure, spectra, magnetism, non-linear optical properties and DFT calculations of a bis(dithiolene)nickel(III) anion salt with substituted isoquinolinium
Published in Inorganic and Nano-Metal Chemistry, 2020
Zhi-Cheng Niu, Min Xue, Yong-Xin Xiao, Lu-Si Chen, Yuan-Yuan Zeng, Wen-Xu Zheng, Chun-Lin Ni, Jia-Rong Zhou
Our results display that a novel molecular solid [4CNBzIQl][Ni(mnt)2](1) and crystal structure has been characterized, give positive results for metal dithiolate complexes in magnets and NLO. The crystal structural analysis shows that the Ni(III) ions form a 1 D zigzag alternating chain within a [Ni(mnt)2]− column through intermolecular Ni···S and π···π interactions. Upon the temperature is lowered, the non-uniform chain has been compressed with the change of Ni···Ni distance. The average crystallized size of 40.4 nm confirming the nanocrystalline of the title compound by using Scherrer’s equation. UV − Vis spectral analysis was used to determine the band gap energy, and the NLO effect of the compound predicted using DFT has revealed that the first hyperpolarisability βtot of the compound is obviously higher than that of the reference crystal KDP, showing that the crystal compound is positive to work as NLO material in the UV region. Magnetic susceptibility measurements confirm that 1 exhibits a spin gap transition with Δ/kb = 435.12 K around 128 K. Overall, according to the present investigation, it is concluded that [4CNBzIQl][Ni(mnt)2] is a new candidate for NLO and magnetic device application.