scholarly journals r2SCAN-3c: An Efficient “Swiss Army Knife” Composite Electronic-Structure Method

2020 ◽  
Author(s):  
Stefan Grimme ◽  
Andreas Hansen ◽  
Sebastian Ehlert ◽  
Jan-Michael Mewes
Keyword(s):  
Electronic Structure ◽  
Density Functional ◽  
Chemical Space ◽  
Noncovalent Interactions ◽  
New Method ◽  
Basis Set ◽  
Basis Set Superposition Error ◽  
Benchmark Database ◽  
The Cost ◽  
Conformational Energies

The recently proposed second revision of the SCAN meta-GGA density-functional approximation (DFA) {Furness et al., J. Phys. Chem. Lett. 2020, 11, 8208-8215, termed r<sup>2</sup>SCAN} is used to construct an efficient composite electronic-structure method termed r<sup>2</sup>SCAN-3c, expanding the "3c'' series (hybrid: HSE/PBEh-3c, GGA: B97-3c, HF: HF-3c) to themGGA level. To this end, the unaltered r<sup>2</sup>SCAN functional is combined with a tailor-made <br>triple-zeta Gaussian AO-basis as well as with refitted D4 and gCP corrections for London-dispersion and basis-set superposition error. The performance of the new method is evaluated for the GMTKN55 thermochemical database covering large parts of chemical space with about 1500 <br>data points, as well as additional benchmarks for noncovalent interactions, organometallic reactions, lattice energies of organic molecules and ices, as well as for the adsorption on polar salt and non-polar coinage-metal surfaces. These comprehensive tests reveal a spectacular performance and robustness of r<sup>2</sup>SCAN-3c for reaction energies and noncovalent interactions in molecular and periodic systems, as well as outstanding conformational energies, and consistent structures. At just one tenth of the cost, r<sup>2</sup>SCAN-3c provides one of the best results of all semi-local DFT/QZ methods ever tested for the GMTKN55 benchmark database. Specifically for reaction and conformational energies as well as for noncovalent interactions, the new method outperforms hybrid-DFT/QZ approaches, compared to which the computational savings are even larger (factor 100-1000).<br>In relation to other "3c'' methods, r<sup>2</sup>SCAN-3c by far surpasses the accuracy of its predecessor B97-3c at only about twice the cost. The perhaps most relevant remaining systematic deviation of r<sup>2</sup>SCAN-3c is due to self-interaction-error, owing to its mGGA nature. However, SIE is notably reduced compared to other (m)GGAs, as is demonstrated for several examples. After all, this remarkably efficient and robust method is chosen as our new group default, replacing previous low-level DFT and partially even expensive high-level methods in most standard applications for systems with up to several hundreds of atoms.<br><br>

scholarly journals r2SCAN-3c: An Efficient “Swiss Army Knife” Composite Electronic-Structure Method

2020 ◽  
Author(s):  
Stefan Grimme ◽  
Andreas Hansen ◽  
Sebastian Ehlert ◽  
Jan-Michael Mewes
Keyword(s):  
Electronic Structure ◽  
Density Functional ◽  
Chemical Space ◽  
Noncovalent Interactions ◽  
New Method ◽  
Basis Set ◽  
Basis Set Superposition Error ◽  
Benchmark Database ◽  
The Cost ◽  
Conformational Energies

The recently proposed second revision of the SCAN meta-GGA density-functional approximation (DFA) {Furness et al., J. Phys. Chem. Lett. 2020, 11, 8208-8215, termed r<sup>2</sup>SCAN} is used to construct an efficient composite electronic-structure method termed r<sup>2</sup>SCAN-3c, expanding the "3c'' series (hybrid: HSE/PBEh-3c, GGA: B97-3c, HF: HF-3c) to themGGA level. To this end, the unaltered r<sup>2</sup>SCAN functional is combined with a tailor-made <br>triple-zeta Gaussian AO-basis as well as with refitted D4 and gCP corrections for London-dispersion and basis-set superposition error. The performance of the new method is evaluated for the GMTKN55 thermochemical database covering large parts of chemical space with about 1500 <br>data points, as well as additional benchmarks for noncovalent interactions, organometallic reactions, lattice energies of organic molecules and ices, as well as for the adsorption on polar salt and non-polar coinage-metal surfaces. These comprehensive tests reveal a spectacular performance and robustness of r<sup>2</sup>SCAN-3c for reaction energies and noncovalent interactions in molecular and periodic systems, as well as outstanding conformational energies, and consistent structures. At just one tenth of the cost, r<sup>2</sup>SCAN-3c provides one of the best results of all semi-local DFT/QZ methods ever tested for the GMTKN55 benchmark database. Specifically for reaction and conformational energies as well as for noncovalent interactions, the new method outperforms hybrid-DFT/QZ approaches, compared to which the computational savings are even larger (factor 100-1000).<br>In relation to other "3c'' methods, r<sup>2</sup>SCAN-3c by far surpasses the accuracy of its predecessor B97-3c at only about twice the cost. The perhaps most relevant remaining systematic deviation of r<sup>2</sup>SCAN-3c is due to self-interaction-error, owing to its mGGA nature. However, SIE is notably reduced compared to other (m)GGAs, as is demonstrated for several examples. After all, this remarkably efficient and robust method is chosen as our new group default, replacing previous low-level DFT and partially even expensive high-level methods in most standard applications for systems with up to several hundreds of atoms.<br><br>

scholarly journals r2SCAN-3c: An Efficient “Swiss Army Knife” Composite Electronic-Structure Method

2020 ◽  
Author(s):  
Stefan Grimme ◽  
Andreas Hansen ◽  
Sebastian Ehlert ◽  
Jan-Michael Mewes
Keyword(s):  
Electronic Structure ◽  
Density Functional ◽  
Chemical Space ◽  
Noncovalent Interactions ◽  
New Method ◽  
Basis Set ◽  
Basis Set Superposition Error ◽  
Benchmark Database ◽  
The Cost ◽  
Conformational Energies

The recently proposed second revision of the SCAN meta-GGA density-functional approximation (DFA) {Furness et al., J. Phys. Chem. Lett. 2020, 11, 8208-8215, termed r<sup>2</sup>SCAN} is used to construct an efficient composite electronic-structure method termed r<sup>2</sup>SCAN-3c, expanding the "3c'' series (hybrid: HSE/PBEh-3c, GGA: B97-3c, HF: HF-3c) to themGGA level. To this end, the unaltered r<sup>2</sup>SCAN functional is combined with a tailor-made <br>triple-zeta Gaussian AO-basis as well as with refitted D4 and gCP corrections for London-dispersion and basis-set superposition error. The performance of the new method is evaluated for the GMTKN55 thermochemical database covering large parts of chemical space with about 1500 <br>data points, as well as additional benchmarks for noncovalent interactions, organometallic reactions, lattice energies of organic molecules and ices, as well as for the adsorption on polar salt and non-polar coinage-metal surfaces. These comprehensive tests reveal a spectacular performance and robustness of r<sup>2</sup>SCAN-3c for reaction energies and noncovalent interactions in molecular and periodic systems, as well as outstanding conformational energies, and consistent structures. At just one tenth of the cost, r<sup>2</sup>SCAN-3c provides one of the best results of all semi-local DFT/QZ methods ever tested for the GMTKN55 benchmark database. Specifically for reaction and conformational energies as well as for noncovalent interactions, the new method outperforms hybrid-DFT/QZ approaches, compared to which the computational savings are even larger (factor 100-1000).<br>In relation to other "3c'' methods, r<sup>2</sup>SCAN-3c by far surpasses the accuracy of its predecessor B97-3c at only about twice the cost. The perhaps most relevant remaining systematic deviation of r<sup>2</sup>SCAN-3c is due to self-interaction-error, owing to its mGGA nature. However, SIE is notably reduced compared to other (m)GGAs, as is demonstrated for several examples. After all, this remarkably efficient and robust method is chosen as our new group default, replacing previous low-level DFT and partially even expensive high-level methods in most standard applications for systems with up to several hundreds of atoms.<br><br>

scholarly journals A look at the density functional theory zoo with the advanced GMTKN55 database for general main group thermochemistry, kinetics and noncovalent interactions

2017 ◽  
Vol 19 (48) ◽  
pp. 32184-32215 ◽  
Author(s):  
Lars Goerigk ◽  
Andreas Hansen ◽  
Christoph Bauer ◽  
Stephan Ehrlich ◽  
Asim Najibi ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Noncovalent Interactions ◽  
Main Group ◽  
Density Functionals ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Benchmark Database ◽  
Electronic Structure Methods

We present the updated and extended GMTKN55 benchmark database for more accurate and extensive energetic evaluation of density functionals and other electronic structure methods with detailed guidelines for method users.

scholarly journals Distinctive Supramolecular Features of β-Cyclodextrin Inclusion Complexes with Antidepressants Protriptyline and Maprotiline: A Comprehensive Structural Investigation

2021 ◽  
Vol 14 (8) ◽  
pp. 812
Author(s):  
Thammarat Aree
Keyword(s):  
Inclusion Complexes ◽  
Density Functional ◽  
Water Solubility ◽  
Geometry Optimization ◽  
Binding Constants ◽  
Basis Set ◽  
Full Geometry Optimization ◽  
Basis Set Superposition Error ◽  
X Ray ◽  
Molecular Stability

Depression, a global mental illness, is worsened due to the coronavirus disease 2019 (COVID-2019) pandemic. Tricyclic antidepressants (TCAs) are efficacious for the treatment of depression, even though they have more side effects. Cyclodextrins (CDs) are powerful encapsulating agents for improving molecular stability, water solubility, and lessening the undesired effects of drugs. Because the atomic-level understanding of the β-CD–TCA inclusion complexes remains elusive, we carried out a comprehensive structural study via single-crystal X-ray diffraction and density functional theory (DFT) full-geometry optimization. Here, we focus on two complexes lining on the opposite side of the β-CD–TCA stability spectrum based on binding constants (Kas) in solution, β-CD–protriptyline (PRT) 1—most stable and β-CD–maprotiline (MPL) and 2—least stable. X-ray crystallography unveiled that in the β-CD cavity, the PRT B-ring and MPL A-ring are aligned at a nearly perfect right angle against the O4 plane and primarily maintained in position by intermolecular C–H···π interactions. The increased rigidity of the tricyclic cores is arising from the PRT -CH=CH- bridge widens, and the MPL -CH2–CH2- flexure narrows the butterfly angles, facilitating the deepest and shallower insertions of PRT B-ring (1) and MPL A-ring (2) in the distorted round β-CD cavity for better complexation. This is indicated by the DFT-derived complex stabilization energies (ΔEstbs), although the complex stability orders based on Kas and ΔEstbs are different. The dispersion and the basis set superposition error (BSSE) corrections were considered to improve the DFT results. Plus, the distinctive 3D arrangements of 1 and 2 are discussed. This work provides the first crystallographic evidence of PRT and MPL stabilized in the β-CD cavity, suggesting the potential application of CDs for efficient drug delivery.

scholarly journals Accuracy and Reliability in the Simulation of Vibrational Spectra: A Comprehensive Benchmark of Energies and Intensities Issuing From Generalized Vibrational Perturbation Theory to Second Order (GVPT2)

2021 ◽  
Vol 8 ◽  
Author(s):  
Qin Yang ◽  
Marco Mendolicchio ◽  
Vincenzo Barone ◽  
Julien Bloino
Keyword(s):  
Perturbation Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Computational Cost ◽  
Theoretical Data ◽  
Infrared Region ◽  
Second Order ◽  
Basis Set ◽  
Molecular Systems ◽  
The Impact

Vibrational spectroscopy represents an active frontier for the identification and characterization of molecular species in the context of astrochemistry and astrobiology. As new missions will provide more data over broader ranges and at higher resolution, especially in the infrared region, which could be complemented with new spectrometers in the future, support from laboratory experiments and theory is crucial. In particular, computational spectroscopy is playing an increasing role in deepening our understanding of the origin and nature of the observed bands in extreme conditions characterizing the interstellar medium or some planetary atmospheres, not easily reproducible on Earth. In this connection, the best compromise between reliability, feasibility and ease of interpretation is still a matter of concern due to the interplay of several factors in determining the final spectral outcome, with larger molecular systems and non-covalent complexes further exacerbating the dichotomy between accuracy and computational cost. In this context, second-order vibrational perturbation theory (VPT2) together with density functional theory (DFT) has become particularly appealing. The well-known problem of the reliability of exchange-correlation functionals, coupled with the treatment of resonances in VPT2, represents a challenge for the determination of standardized or “black-box” protocols, despite successful examples in the literature. With the aim of getting a clear picture of the achievable accuracy and reliability of DFT-based VPT2 calculations, a multi-step study will be carried out here. Beyond the definition of the functional, the impact of the basis set and the influence of the resonance treatment in VPT2 will be analyzed. For a better understanding of the computational aspects and the results, a short summary of vibrational perturbation theory and the overall treatment of resonances for both energies and intensities will be given. The first part of the benchmark will focus on small molecules, for which very accurate experimental and theoretical data are available, to investigate electronic structure calculation methods. Beyond the reliability of energies, widely used for such systems, the issue of intensities will also be investigated in detail. The best performing electronic structure methods will then be used to treat larger molecular systems, with more complex topologies and resonance patterns.

A density functional approach toward structural features and properties of C20…N2X2 (X = H, F, Cl, Br, Me) molecules

2014 ◽  
Vol 13 (04) ◽  
pp. 1450023 ◽  
Author(s):  
Reza Ghiasi ◽  
Morteza Zaman Fashami ◽  
Amir Hossein Hakimioun
Keyword(s):  
Density Functional ◽  
Chemical Shifts ◽  
Geometry Optimization ◽  
Structural Features ◽  
Nbo Analysis ◽  
Basis Set ◽  
Basis Sets ◽  
Basis Set Superposition Error ◽  
Homo And Lumo ◽  
Lowest Unoccupied Molecular Orbitals

In this work, the interaction of C 20 with N 2 X 2 ( X = H , F , Cl , Br , Me ) molecules has been explored using the B3LYP, M062x methods and 6-311G(d,p) and 6-311+G(d,p) basis sets. The interaction energies (IEs) obtained with standard method were corrected by basis set superposition error (BSSE) during the geometry optimization for all molecules at the same levels of theory. It was found C 20… N 2 H 2 interaction is stronger than the interaction of other N 2 X 2 ( X = F , Cl , Br , Me ) with C 20. Highest occupied and lowest unoccupied molecular orbitals (HOMO and LUMO, respectively) levels are illustrated by density of states spectra (DOS). The nucleus-independent chemical shifts (NICSs) confirm that C 20… N 2 X 2 molecules exhibit aromatic characteristics. Geometries obtained from DFT calculations were used to perform NBO analysis. Also, 14 N NQR parameters of the C 20… N 2 X 2 molecules are predicted.

scholarly journals Double-Hybrid DFT Functionals for the Condensed Phase: Gaussian and Plane Waves Implementation and Evaluation

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5174
Author(s):  
Frederick Stein ◽  
Jürg Hutter ◽  
Vladimir V. Rybkin
Keyword(s):  
Condensed Phase ◽  
Density Functional ◽  
Plane Waves ◽  
Basis Set ◽  
Basis Sets ◽  
Density Functionals ◽  
Basis Set Superposition Error ◽  
Super Cell ◽  
Long Range Interactions ◽  
Function Correlation

Intermolecular interactions play an important role for the understanding of catalysis, biochemistry and pharmacy. Double-hybrid density functionals (DHDFs) combine the proper treatment of short-range interactions of common density functionals with the correct description of long-range interactions of wave-function correlation methods. Up to now, there are only a few benchmark studies available examining the performance of DHDFs in condensed phase. We studied the performance of a small but diverse selection of DHDFs implemented within Gaussian and plane waves formalism on cohesive energies of four representative dispersion interaction dominated crystal structures. We found that the PWRB95 and ωB97X-2 functionals provide an excellent description of long-ranged interactions in solids. In addition, we identified numerical issues due to the extreme grid dependence of the underlying density functional for PWRB95. The basis set superposition error (BSSE) and convergence with respect to the super cell size are discussed for two different large basis sets.

A DENSITY FUNCTIONAL THEORY INVESTIGATION ON THE TAUTOMERS AND CRYSTAL OF 2-DIAZO-4,6-DINITROPHENOL

2004 ◽  
Vol 03 (04) ◽  
pp. 599-607 ◽  
Author(s):  
XUE-HAI JU ◽  
HE-MING XIAO
Keyword(s):  
Density Functional ◽  
Density Functional Method ◽  
Lattice Energy ◽  
Functional Method ◽  
Basis Set ◽  
Functional Theory ◽  
Basis Set Superposition Error ◽  
Conduction Bands ◽  
Valence Bands ◽  
Good Agreement

Density functional method was applied to the study of the highly efficient primary explosive 2-diazo-4,6-dinitrophenol (DDNP) in both gaseous tautomers and its bulk state. Two stable tautomers were located. It was found that the structure (I) with open diazo, i.e. with linear CNN, is more stable than that with diazo ring tautomer (II) of DDNP. The structure I is in good agreement with the structure in the bulk. The lattice energy is -89.01 kJ/mol, and this value drops to -83.29 kJ/mol when a 50% correction of the basis set superposition error was adopted. The frontier bands are quite flat. The carbon atoms in DDNP make up the upper valence bands. While the lower conduction bands mainly consist of carbon and diazo N atoms. The bond populations of C–N bonds (both C–Nitro and C–Diazo) are much less than those of the other bonds and the detonation may be initiated through the breakdown of C–N bonds.

Binding Energies of Organic Charge-Transfer Complexes Calculated by First-Principles Methods

1998 ◽  
Vol 63 (8) ◽  
pp. 1223-1244 ◽  
Author(s):  
Cordula Rauwolf ◽  
Achim Mehlhorn ◽  
Jürgen Fabian
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Ground State ◽  
Density Functional ◽  
Binding Energies ◽  
Basis Set ◽  
Dispersion Energy ◽  
Functional Theory ◽  
Basis Set Superposition Error ◽  
Donor And Acceptor

Weak interactions between organic donor and acceptor molecules resulting in cofacially-stacked aggregates ("CT complexes") were studied by second-order many-body perturbation theory (MP2) and by gradient-corrected hybrid Hartree-Fock/density functional theory (B3LYP exchange-correlation functional). The complexes consist of tetrathiafulvalene (TTF) and related compounds and tetracyanoethylene (TCNE). Density functional theory (DFT) and MP2 molecular equilibrium geometries of the component structures are calculated by means of 6-31G*, 6-31G*(0.25), 6-31++G**, 6-31++G(3df,2p) and 6-311G** basis sets. Reliable molecular geometries are obtained for the donor and acceptor compounds considered. The geometries of the compounds were kept frozen in optimizing aggregate structures with respect to the intermolecular distance. The basis set superposition error (BSSE) was considered (counterpoise correction). According to the DFT and MP2 calculations laterally-displaced stacks are more stable than vertical stacks. The charge transfer from the donor to the acceptor is small in the ground state of the isolated complexes. The cp-corrected binding energies of TTF/TCNE amount to -1.7 and -6.3 kcal/mol at the DFT(B3LYP) and MP2(frozen) level of theory, respectively (6-31G* basis set). Larger binding energies were obtained by Hobza's 6-31G*(0.25) basis set. The larger MP2 binding energies suggest that the dispersion energy is underestimated or not considered by the B3LYP functional. The energy increases when S in TTF/TCNE is replaced by O or NH but decreases with substitution by Se. The charge-transferred complexes in the triplet state are favored in the vertical arrangement. Self-consistent-reaction-field (SCRF) calculations predicted a gain in binding energy with solvation for the ground-state complex. The ground-state charge transfer between the components is increased up to 0.8 e in polar solvents.

Sign in / Sign up

Export Citation Format

Share Document