Ligand Effects on the Regioselectivity of Rhodium-Catalyzed Hydroformylation: Density Functional Calculations Illuminate the Role of Long-Range Noncovalent Interactions

2014 ◽  
Vol 33 (16) ◽  
pp. 4183-4191 ◽  
Author(s):  
Manoj Kumar ◽  
Raghunath V. Chaudhari ◽  
Bala Subramaniam ◽  
Timothy A. Jackson
Keyword(s):  
Long Range ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Noncovalent Interactions ◽  
Ligand Effects

Long-range dispersion-corrected density functional for noncovalent interactions

2019 ◽  
Vol 33 (26) ◽  
pp. 1950300 ◽  
Author(s):  
Hong Tang ◽  
Jianmin Tao
Keyword(s):  
Long Range ◽  
Short Range ◽  
Density Functional ◽  
Intramolecular Interaction ◽  
Noncovalent Interactions ◽  
Molecular Complexes ◽  
Generalized Gradient ◽  
Range Interaction ◽  
Large Size ◽  
Vdw Interaction

Noncovalent interactions are important in determining structures and properties of molecular complexes and biological molecules, and for understanding adsorption processes in chemistry and biological science, and are still challenging to conventional density functional theories. In this work, the recently developed Tao-Mo (TM) meta-GGA (generalized gradient approximation) functional is combined with the D3 scheme of long-range van der Waals (vdW) interaction correction and the parameters of damping function are optimized with the S66[Formula: see text]×[Formula: see text]8 set. The resulting TM-D3 method is applied to the medium-sized molecular set S22 and large size molecular complexes set L7 to calculate intramolecular interaction energies. The TM-D3 method produces the best accuracy for the S22 set with a MAE of 0.2 kcal/mol, improving upon the PBE-D3 (MAE[Formula: see text]=[Formula: see text]0.5 kcal/mol), PBE0-D3 (MAE[Formula: see text]=[Formula: see text]0.5 kcal/mol), TPSS-D3 (MAE[Formula: see text]=[Formula: see text]0.4 kcal/mol), M06L (MAE[Formula: see text]=[Formula: see text]0.8 kcal/mol), and SCAN-D3 (MAE[Formula: see text]=[Formula: see text]0.4 kcal/mol) methods. For the large size set L7, the TM-D3 (MAE[Formula: see text]=[Formula: see text]2.1 kcal/mol) also performs better than the PBE-D3 (MAE[Formula: see text]=[Formula: see text]2.6 kcal/mol), SCAN-D3 (2.5 kcal/mol) and M06L (3.0 kcal/mol), but not accurate than the PBE0-D3 (MAE[Formula: see text]=[Formula: see text]0.8 kcal/mol) and TPSS-D3 (MAE[Formula: see text]=[Formula: see text]1.1 kcal/mol). However, overall, the TM-D3 method performs very well with an error of 2.7% of mean binding of the S22 set and an error of 12.6% of the mean binding of the L7 set for the two typical and important medium and large size molecular complex sets. The success of the dispersion-corrected TM functional benefits from the ability of the plain TM functional to capture the short-range vdW interaction or extend the short-range interaction to the middle range, and the right coupling between the TM and the long-range vdW correction D3 scheme, leading to the improved description of noncovalent interactions.

Hydrogen doping in wide-bandgap amorphous In–Ga–O semiconductors

2020 ◽  
Vol 8 (43) ◽  
pp. 15436-15449
Author(s):  
Julia E. Medvedeva ◽  
Bishal Bhattarai
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Molecular Dynamics Simulations ◽  
Long Range ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Structural Transformations ◽  
Wide Bandgap ◽  
Computationally Intensive ◽  
Dynamics Simulations

Microscopic mechanisms of the formation of H defects and their role in passivation of under-coordinated atoms, short- and long-range structural transformations, and the resulting electronic properties of amorphous In–Ga–O with In : Ga = 6 : 4 are investigated using computationally-intensive ab initio molecular dynamics simulations and accurate density-functional calculations.

Chlorine in SiC: Experiment and Theory

2012 ◽  
Vol 717-720 ◽  
pp. 229-232
Author(s):  
Giovanni Alfieri ◽  
Tsunenobu Kimoto
Keyword(s):  
Carrier Concentration ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Electrical Characterization ◽  
Microscopic Structure ◽  
Annealing Study ◽  
P Type ◽  
Theoretical Results

An annealing study, in the 100-1400 C temperature range ,was carried out on Cl-implanted n- or p-type 4H-SiC epilayers. The electrical characterization of the epilayers shows the rise of several deep levels and the role of Cl, on both carrier concentration and defects' microscopic structure, is discussed in the light of theoretical results obtained by density functional calculations performed on a 64-atom cubic SiC supercell.

The role of the CO adsorption on Pt monolayers supported on flat and stepped Au surfaces: a density functional investigation

RSC Advances ◽  
2014 ◽  
Vol 4 (18) ◽  
pp. 9247-9254 ◽  
Author(s):  
Polina Tereshchuk ◽  
Rafael L. H. Freire ◽  
Juarez L. F. Da Silva
Keyword(s):  
Density Functional ◽  
Co Adsorption ◽  
Metal Films ◽  
Chemical Activity ◽  
Ligand Effects ◽  
Ultrathin Metal Films ◽  
Transition Metal Surfaces ◽  
Substrate Strain ◽  
Functional Investigation

Ultrathin metal films supported on transition-metal surfaces have been considered as promising catalysts as their chemical activity can be controlled by substrate strain, composition, and ligand effects, however, our atomistic understanding of the atomic structure of those systems is far from satisfactory.

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