The structural and energetic characteristics of O3–H2O complexes have been investigated by means of B3LYP, MP2, MP4(SDTQ), CCSD(T) and QCISD(T) methods in conjunction with the AUG-cc-pVDZ and AUG-cc-pVTZ basis sets. Six conformers were found for the O3–H2O complex. Two different intermolecular interactions were expected to participate in the formation of complexes, namely conventional O∙∙∙H hyd...

over the past decade, the chemical behavior of flavonoids as antioxidants has become the subject ofintense experimental research. in this paper, we use a quantum-chemical approach to shed light on thereactivity of four poly phenols, benzoic acid, vanilic acid, gallic acid and flavone . in order to establishthe most efficient theoretical methodology, different methods, either hartree—fock-based ...

At the present theoretical study, DFT calculations were performed for elucidating thereaction, absorption energy and the quantum molecular descriptors including electronic chemical potential, chemical hardness, Homo, Lumo, band gap energy (Eg) and finding the most active nitrogen-doped graphene sheet (N-G) for absorption H2S, CH4, N2 and CO2 gases. Finally it found that nitrogen-doped gra...

we report the growth by ion exchange synthesis of zns nanoparticles in mcm-41 matrices using zn (ch3coo)2 and na2s starting sources. the final product (zns/mcm-41) was characterized by x-ray diffraction (xrd) pattern, transmission electron microscopy (tem), scanning electron microscopy (sem), infrared spectrometry (ir) and uv-vis spectroscopy. its crystalline structure and morphology was studie...

the n-(2-benzoyl-phenyl) oxalyl derivatives are important models for studying of three-centered intramolecular hydrogen bonding in organic molecules. the quantum theoretical calculations for two crystal structures of n-(2-benzoyl-phenyl) oxalyl (compounds i and ii) were performed by density functional theory (b3lyp method and 6-311+g* basis set). from the optimized structures, geometric paramet...

This section describes the research efforts and progress made for the implementation and performance of the quantum mechanical reactive scattering application (3D-REACT) across CASA heterogeneous computer environments with nodes that can reside at geographically different locations. This is a scientifically and technically important application. The formalism uses a symmetrized hyperspherical c...

While structures and reactivities of many small molecules can be computed efficiently and accurately using quantum chemical methods, heuristic approaches remain essential for modeling complex structures and large-scale chemical systems. Here, we present a heuristics-aided quantum chemical methodology applicable to complex chemical reaction networks such as those arising in cell metabolism and p...