scholarly journals Adaptive local basis set for Kohn–Sham density functional theory in a discontinuous Galerkin framework I: Total energy calculation

2012 ◽  
Vol 231 (4) ◽  
pp. 2140-2154 ◽  
Author(s):  
Lin Lin ◽  
Jianfeng Lu ◽  
Lexing Ying ◽  
Weinan E
2020 ◽  
Vol 860 ◽  
pp. 282-287
Author(s):  
Wan Nurfadhilah Zaharim ◽  
Shukri Sulaiman ◽  
Saidah Sakinah Mohd Tajudin ◽  
Siti Nuramira Abu Bakar ◽  
Nur Eliana Ismail ◽  
...  

The Density Functional Theory method was employed to investigate the electronic structure and muonium hyperfine interaction of muonium trapped near carbon atom labelled as '5' in cytosine nucleobase. Eighteen different basis sets in combination with B3LYP functional were examined in geometry optimization calculations on the muoniated radical. There are significant quantitative differences in the calculated total energy. The employment of basis set that does not include polarization function produces an optimized structure with high total energy. The 6-311++G(d,p) basis set yielded the lowest total energy as compared to other basis sets. The bond order of muonium trapped at C5 atom is in the range of 0.841 to 0.862. The 6-31G basis set produced the muonium Fermi contact coupling constant that is the closest to the experimental value.


2012 ◽  
Vol 231 (13) ◽  
pp. 4515-4529 ◽  
Author(s):  
Lin Lin ◽  
Jianfeng Lu ◽  
Lexing Ying ◽  
Weinan E

2013 ◽  
Vol 2013 ◽  
pp. 1-3 ◽  
Author(s):  
Frank J. Owens

Copper chloride consists of parallel chains of CuCl2. The chains are sufficiently far apart such that the electronic and magnetic properties of CuCl2 have been approximated as arising from isolated chains. Density functional theory using the LANL2DZ/6-31G* basis set has been used to calculate the total energy of CuCl2 chains having nanometer length. The calculations, which are performed as a function of chain length, predict that chains having ferromagnetic order have a lower energy than chains with no order. Calculations of the band gap as a function of length for the ferromagnetic chains indicate that chains greater than 6 nm may be semiconducting suggesting that nanosized CuCl2 chains have the potential to be magnetic semiconductors.


2019 ◽  
Author(s):  
Kamal Batra ◽  
Stefan Zahn ◽  
Thomas Heine

<p>We thoroughly benchmark time-dependent density- functional theory for the predictive calculation of UV/Vis spectra of porphyrin derivatives. With the aim to provide an approach that is computationally feasible for large-scale applications such as biological systems or molecular framework materials, albeit performing with high accuracy for the Q-bands, we compare the results given by various computational protocols, including basis sets, density-functionals (including gradient corrected local functionals, hybrids, double hybrids and range-separated functionals), and various variants of time-dependent density-functional theory, including the simplified Tamm-Dancoff approximation. An excellent choice for these calculations is the range-separated functional CAM-B3LYP in combination with the simplified Tamm-Dancoff approximation and a basis set of double-ζ quality def2-SVP (mean absolute error [MAE] of ~0.05 eV). This is not surpassed by more expensive approaches, not even by double hybrid functionals, and solely systematic excitation energy scaling slightly improves the results (MAE ~0.04 eV). </p>


1999 ◽  
Vol 23 (8) ◽  
pp. 502-503
Author(s):  
Branko S. Jursic

High level ab initio and density functional theory studies are performed on highly protonated methane species.


Author(s):  
Bole Chen ◽  
Gennady L. Gutsev ◽  
Weiguo Sun ◽  
Xiao-Yu Kuang ◽  
Cheng Lu ◽  
...  

The coalescence of two Fe8N as well as the structure of the Fe16N2 cluster were studied using density functional theory with the generalized gradient approximation and a basis set of...


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3631
Author(s):  
Ahmed M. Deghady ◽  
Rageh K. Hussein ◽  
Abdulrahman G. Alhamzani ◽  
Abeer Mera

The present investigation informs a descriptive study of 1-(4-Hydroxyphenyl) -3-phenylprop-2-en-1-one compound, by using density functional theory at B3LYP method with 6-311G** basis set. The oxygen atoms and π-system revealed a high chemical reactivity for the title compound as electron donor spots and active sites for an electrophilic attack. Quantum chemical parameters such as hardness (η), softness (S), electronegativity (χ), and electrophilicity (ω) were yielded as descriptors for the molecule’s chemical behavior. The optimized molecular structure was obtained, and the experimental data were matched with geometrical analysis values describing the molecule’s stable structure. The computed FT-IR and Raman vibrational frequencies were in good agreement with those observed experimentally. In a molecular docking study, the inhibitory potential of the studied molecule was evaluated against the penicillin-binding proteins of Staphylococcus aureus bacteria. The carbonyl group in the molecule was shown to play a significant role in antibacterial activity, four bonds were formed by the carbonyl group with the key protein of the bacteria (three favorable hydrogen bonds plus one van der Waals bond) out of six interactions. The strong antibacterial activity was also indicated by the calculated high binding energy (−7.40 kcal/mol).


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