نتایج جستجو برای: pbe0 13

تعداد نتایج: 332776  

2008
Ibrahim N. Hassan Bohari M. Yamin Mohammad B. Kassim

The title compound, C(13)H(16)N(2)O(3)S, is a thio-urea derivative with benzoyl and propoxycarbonyl-methyl groups attached to the two terminal N atoms. These groups adopt trans and cis configurations, respectively, with respect to the S atom across the thio-urea C-N bonds. The compound crystallizes in the P2(1)/c space group with Z = 8, resulting in two unique molecules in the asymmetric unit l...

2017
Isaac Alcón Daniel Reta Iberio de P. R. Moreira Stefan T. Bromley

1. Total energy variation vs. twisting aryl rings in TPM and PTM molecules Fig. 1 The three aryl rings of the triphenylmethyl (TPM), (a) and perchloro-triarylmethyl (PTM), (b) TAM derivatives were systematically twisted from 20 to 90 degrees while relaxing the rest of the molecular structure by constrained optimizations. These calculations were done using the PBE0 hybrid functional 1 and the 6-...

Journal: :Dalton transactions 2010
Ragnar Bjornsson Michael Bühl

Electric field gradients (EFGs) were computed for the first-row transition metal nuclei in Cr(C(6)H(6))(CO)(3), MnO(3)F, Mn(CO)(5)H, MnCp(CO)(3), Co(CO)(4)H, Co(CO)(3)(NO) and VCp(CO)(4), for which experimental gas-phase data (in form of nuclear quadrupole coupling constants) are available from microwave spectroscopy. A variety of exchange-correlation functionals were assessed, among which rang...

Journal: :Journal of chemical theory and computation 2013
Fabien Bruneval Miguel A L Marques

The GW approximation is nowadays being used to obtain accurate quasiparticle energies of atoms and molecules. In practice, the GW approximation is generally evaluated perturbatively, based on a prior self-consistent calculation within a simpler approximation. The final result thus depends on the choice of the self-consistent mean-field chosen as a starting point. Using a recently developed GW c...

2013
Martin Schlipf Markus Betzinger Marjana Ležaić Christoph Friedrich Stefan Blügel Peter Grünberg

We analyze the structural, electronic, and magnetic properties of the europium chalcogenide series EuX (X = O, S, Se, and Te) using density-functional theory (DFT). To describe the localized 4f states of Eu, we utilize the parameter-free PBE0 and HSE hybrid functionals and found a systematic qualitative and quantitative improvement over the conventional local and semilocal functionals. Both hyb...

2018
Barbara Franczuk Witold Danikiewicz

Ion-molecule reactions of Me2S2 with a wide range of aliphatic carbanions differing by structure and proton affinity values have been studied in the gas phase using mass spectrometry techniques and DFT calculations. The analysis of the spectra shows a variety of product ions formed via different reaction mechanisms, depending on the structure and proton affinity of the carbanion. Product ions o...

Journal: :Physical chemistry chemical physics : PCCP 2014
Paola Nava Yannick Carissan

The influence of several substituents on the ring-opening elementary step of cyclobutene-like systems is analyzed computationally in detail. We focus on trans-1,2-disiloxycyclobutene-like molecules. Electronic effects (hyperconjugation and π delocalization) and geometrical constraints are decoupled and allow for an instructive analysis. It is found that the energy difference between closed and ...

Journal: :The Journal of chemical physics 2007
Biswajit Santra Angelos Michaelides Matthias Scheffler

The ability of several density-functional theory (DFT) exchange-correlation functionals to describe hydrogen bonds in small water clusters (dimer to pentamer) in their global minimum energy structures is evaluated with reference to second order Moller-Plesset perturbation theory (MP2). Errors from basis set incompleteness have been minimized in both the MP2 reference data and the DFT calculatio...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید