The Experts below are selected from a list of 48 Experts worldwide ranked by ideXlab platform
Angelo Gavezzotti - One of the best experts on this subject based on the ideXlab platform.
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Towards a realistic model for the quantitative evaluation of intermolecular potentials and for the rationalization of organic crystal structures. Part II. Crystal energy landscapes
CrystEngComm, 2003Co-Authors: Angelo GavezzottiAbstract:Many crystal structures were generated by a computer predictor for naphthalene, naphthoquinone, 1,2-dichlorobenzene, 2,3-dimethylbenzoic acid, parabanic acid and pyridine, and the lattice energies were then calculated by standard atom–atom potentials, by point-charge models, and by the SCDS-Pixel method. Using results from the latter approach, the relative importance of coulombic, polarization, dispersion and repulsion energies in crystals is discussed in relationship with the chemical characteristics of the Constituent Molecule, with crystal density, and with some key crystal structural factors like interplanar angles and some intermolecular distances believed to be indicators of crystal stabilization. In general, intermolecular interactions are better discussed when considering the electron density of large molecular moieties or of entire Molecules, than when considering atom–atom distances. Significant comparisons between atom–atom energies and the more accurate Pixel energies are presented. The performance of the Pixel-SCDS method in ranking crystal energies against experimental structures, in the so-called crystal structure prediction exercise, is comparable to, and sometimes better than that of atom–atom force fields.
Nanrong Zhao - One of the best experts on this subject based on the ideXlab platform.
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prediction and simulation of compressive shocks with lower perturbed density for increasing shock strength in real gases
Physical Review E, 2010Co-Authors: Shigeru Taniguchi, Tommaso Ruggeri, Andrea Mentrelli, Masaru Sugiyama, Nanrong ZhaoAbstract:In this paper we predict and simulate a peculiar type of compressive shock in a real gas modeled by the van der Waals constitutive equation. This shock produces a phase transition from the gas to the liquid phase and, under some special circumstances, back to the gas phase. This shock has a quite unusual property that when the perturbed pressure (the pressure after a shock) increases, the perturbed density decreases and tends to a limit value from above, in contrast with the ordinary well-known compressive shock in which the density tends to the limit value from below. To achieve such a compressive upper shock, it is necessary to choose the unperturbed state (the state before the shock) in a very thin region in the $\ensuremath{\rho}p$ plane, characterized by low values of density and pressure, near the gas-liquid coexistence curve. This region, which depends on the internal degrees of freedom of a Constituent Molecule, is completely identified.
Heming Xiao - One of the best experts on this subject based on the ideXlab platform.
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Surface-Induced Energetics, Electronic Structure, and Vibrational Properties of β-HMX Nanoparticles: A Computational Study
The Journal of Physical Chemistry C, 2016Co-Authors: Zhichao Liu, Weihua Zhu, Heming XiaoAbstract:Surface chemistry plays an prominent part in the behaviors of condensed phase materials and nanoparticles. A combinational strategy based on density-functional theory (DFT) and density-functional tight-binding (DFTB) methods was used to study the surface-induced effect on the energetics, electronic structure, and vibrational properties of a series of β-octatetramethylene tetranitramine nanoparticles (β-HMX NPs). A comparative analysis of the NPs, isolated Constituent Molecule, and periodic solid-state phase of β-HMX indicates that the NPs possess quite different characteristics from either the Constituent Molecule or the bulk crystal. The anitsotropy of surface energies, enthalpy of sublimation, and melting point for the NPs are predicted. The surface-induced surface states of the HMX NPs lead to a significant reduction of the energy gap and provide active sites at surfaces. The vibrational properties of the experimentally determined strong modes are compared and discussed among the NPs, gas phase, and so...
Hiroshi Orhui - One of the best experts on this subject based on the ideXlab platform.
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Chiral molecular patterns of self-assembled ion pairs composed of (R,S), (S)-16-methyloctadecanoic acid and 4,4′-bipyridine
Chemical Communications, 2000Co-Authors: Pu Qian, Hiroshi Nanjo, Toshiro Yokoyama, Toshishige M. Suzuki, Kazuaki Akasaka, Hiroshi OrhuiAbstract:Self-assembled monolayers of stearic acid, (R,S) and (S)-16-methyloctadecanoic acid ion-paired with 4,4′-bipyridine have been observed on a solution–graphite interface by a scanning tunneling microscope (STM) and the observed macro-scale molecular patterns have been interpreted in terms of absolute chirality of the Constituent Molecule.
Matthew D. King - One of the best experts on this subject based on the ideXlab platform.
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Cataloguing the Energetic Contributions to the Supramolecular Assembly of para-Substituted N,N′-Diphenylureas and Their Organometallic Derivatives in the Solid State: A Density Functional Theory Approach
Crystal Growth & Design, 2020Co-Authors: Jenny W. Fothergill, Adam C. Colson, Matthew D. KingAbstract:Crystal engineering relies on the predictability of the elaborate interplay of cohesive and conformational energies driven by both intra- and intermolecular interactions of the Constituent Molecule...