Results 251 to 260 of about 7,871,511 (280)

Quantum Chemical Modeling of Zeolite-Catalyzed Methylation Reactions: Toward Chemical Accuracy for Barriers

Journal of the American Chemical Society, 2008
The methylation of ethene, propene, and t-2-butene by methanol over the acidic microporous H-ZSM-5 catalyst has been investigated by a range of computational methods. Density functional theory (DFT) with periodic boundary conditions (PBE functional) fails to describe the experimentally determined decrease of apparent energy barriers with the alkene ...
Stian, Svelle, Christian, Tuma, Xavier, Rozanska, Torsten, Kerber, Joachim, Sauer   +4 more
openaire   +2 more sources

Achieving Chemical Accuracy with Coupled-Cluster Theory

1995
Due to formal and computational advances in coupled-cluster theory over the past few years, it is now possible to obtain very accurate molecular geometries, vibrational frequencies, heats of formation, binding energies, and vertical electronic excitation energies. For example, based on statistical analyses of a large number of calculations, it is shown
Timothy J. Lee, Gustavo E. Scuseria
openaire   +1 more source

Improving chemical accuracy with neural networks

Nature Computational Science, 2021
openaire   +2 more sources

Precision and accuracy of chemical analysis of silicate rocks

Geochimica et Cosmochimica Acta, 1953
Replicate analyses by 35 laboratories of a granite and a diabase, especially prepared as standards, give means and standard deviations which should be invaluable for calibration purposes in spectrochemical and chemical laboratories. It is clearly shown that relative error varies inversely with concentration of the constituent (e.g.
openaire   +1 more source

A Survey of the Accuracy of Chemical Analyses in Clinical Laboratories

American Journal of Clinical Pathology, 1947
W P, BELK, F W, SUNDERMAN
openaire   +2 more sources

Group Contribution Revisited: The Enthalpy of Formation of Organic Compounds with “Chemical Accuracy” Part II

AppliedChem, 2021
Rob Meier
exaly  

Control strategy of machining efficiency and accuracy in weak-chemical-coordinated-thickening polishing (WCCTP) process on spherical curved 9Cr18 components

Journal of Manufacturing Processes, 2022

exaly  

Transition-Metal Systems in Biochemistry Studied by High-Accuracy Quantum Chemical Methods

Chemical Reviews, 2000
Per Siegbahn, Margareta Blomberg
exaly  

Chemical accuracy from ‘Coulomb hole’ extrapolated molecular quantum-mechanical calculations

Journal of Molecular Structure, 2001
Trygve Helgaker, Wim Klopper, P Jørgensen   +2 more
exaly  

Accuracy of certain physico-chemical experiments

Journal of Chemical Education, 1932
openaire   +1 more source