1
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Santra G, Martin JML. Do Double-Hybrid Functionals Benefit from Regularization in the PT2 Term? Observations from an Extensive Benchmark. J Phys Chem Lett 2022; 13:3499-3506. [PMID: 35417181 PMCID: PMC9036584 DOI: 10.1021/acs.jpclett.2c00718] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We put to the test a recent suggestion [Shee, J., et al. J. Phys. Chem. Lett. 2021, 12 (50), 12084-12097] that MP2 regularization might improve the performance of double-hybrid density functionals. Using the very large and chemically diverse GMTKN55 benchmark, we find that κ-regularization is indeed beneficial at lower percentages of Hartree-Fock exchange, especially if spin-component scaling is not applied [such as in B2GP-PLYP or ωB97M(2)]. This benefit dwindles for DSD and DOD functionals and vanishes entirely in the ∼70% HF exchange region optimal for them.
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2
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Rudshteyn B, Weber JL, Coskun D, Devlaminck PA, Zhang S, Reichman DR, Shee J, Friesner RA. Calculation of Metallocene Ionization Potentials via Auxiliary Field Quantum Monte Carlo: Toward Benchmark Quantum Chemistry for Transition Metals. J Chem Theory Comput 2022; 18:2845-2862. [PMID: 35377642 PMCID: PMC9123894 DOI: 10.1021/acs.jctc.1c01071] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The accurate ab initio prediction of ionization energies is essential to understanding the electrochemistry of transition metal complexes in both materials science and biological applications. However, such predictions have been complicated by the scarcity of gas phase experimental data, the relatively large size of the relevant molecules, and the presence of strong electron correlation effects. In this work, we apply all-electron phaseless auxiliary-field quantum Monte Carlo (ph-AFQMC) utilizing multideterminant trial wave functions to six metallocene complexes to compare the computed adiabatic and vertical ionization energies with experimental results. We find that ph-AFQMC yields mean absolute errors (MAEs) of 1.69 ± 1.02 kcal/mol for the adiabatic energies and 2.85 ± 1.13 kcal/mol for the vertical energies. We also carry out density functional theory (DFT) calculations using a variety of functionals, which yields MAEs of 3.62-6.98 kcal/mol and 3.31-9.88 kcal/mol, as well as one variant of localized coupled cluster calculations (DLPNO-CCSD(T0) with moderate PNO cutoffs), which has MAEs of 4.96 and 6.08 kcal/mol, respectively. We also test the reliability of DLPNO-CCSD(T0) and DFT on acetylacetonate (acac) complexes for adiabatic energies measured in the same manner experimentally, and we find higher MAEs, ranging from 4.56 to 10.99 kcal/mol (with a different ordering) for DFT and 6.97 kcal/mol for DLPNO-CCSD(T0). Finally, by utilizing experimental solvation energies, we show that accurate reduction potentials in solution for the metallocene series can be obtained from the AFQMC gas phase results.
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Affiliation(s)
- Benjamin Rudshteyn
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - John L Weber
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Dilek Coskun
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Pierre A Devlaminck
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Shiwei Zhang
- Center for Computational Quantum Physics, Flatiron Institute, 162 Fifth Avenue, New York, New York 10010, United States.,Department of Physics, College of William and Mary, Williamsburg, Virginia 23187, United States
| | - David R Reichman
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - James Shee
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Richard A Friesner
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
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3
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Seeger ZL, Izgorodina EI. A DLPNO-CCSD(T) benchmarking study of intermolecular interactions of ionic liquids. J Comput Chem 2022; 43:106-120. [PMID: 34687062 DOI: 10.1002/jcc.26776] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 11/11/2022]
Abstract
The accuracy of correlation energy recovered by coupled cluster single-, double-, and perturbative triple-excitations, CCSD(T), has led to the method being considered the gold standard of computational chemistry. The application of CCSD(T) has been limited to medium-sized molecular systems due to its steep scaling with molecular size. The recent development of alternative domain-based local pair natural orbital coupled-cluster method, DLPNO-CCSD(T), has significantly broadened the range of chemical systems to which CCSD(T) level calculations can be applied. Condensed systems such as ionic liquids (ILs) have a large contribution from London dispersion forces of up to 150 kJ mol-1 in large-scale clusters. Ionic liquids show appreciable charge transfer effects that result in the increased valence orbital delocalization over the entire ionic network, raising the question whether the application of methods based on localized orbitals is reliable for these semi-Coulombic materials. Here the performance of DLPNO-CCSD(T) is validated for the prediction of correlation interaction energies of two data sets incorporating single-ion pairs of protic and aprotic ILs. DLPNO-CCSD(T) produced results within chemical accuracy with tight parameter settings and a non-iterative treatment of triple excitations. To achieve spectroscopic accuracy of 1 kJ mol-1 , especially for hydrogen-bonded ILs and those containing halides, the DLPNO settings had to be increased by two orders of magnitude and include the iterative treatment of triple excitations, resulting in a 2.5-fold increase in computational cost. Two new sets of parameters are put forward to produce the performance of DLPNO-CCSD(T) within chemical and spectroscopic accuracy.
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Affiliation(s)
- Zoe L Seeger
- School of Chemistry, Monash University, Clayton, Victoria, Australia
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4
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Efremenko I, Martin JML. Coupled Cluster Benchmark of New DFT and Local Correlation Methods: Mechanisms of Hydroarylation and Oxidative Coupling Catalyzed by Ru(II, III) Chloride Carbonyls. J Phys Chem A 2021; 125:8987-8999. [PMID: 34586809 DOI: 10.1021/acs.jpca.1c05124] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have evaluated a set of accurate canonical CCSD(T) energies for stationary points on the potential energy surface for Ru(II, III) chloride carbonyl catalysis of two competing reactions between benzene and methyl acrylate (MA), namely, hydroarylation and oxidative coupling. We have then applied this set to evaluate the performance of localized orbital coupled-cluster methods and several new and common density functionals. We find that (a) DLPNO-CCSD(T) with TightPNO cutoffs is an acceptable substitute for full canonical CCSD(T) calculations on this system; (b) for the closed-shell systems where it could be applied, LNO-CCSD(T) with tight convergence criteria is very close to the canonical results; (c) the recent ωB97X-V and ωB97M-V functionals exhibit superior performance to commonly used DFT functionals in both closed- and open-shell calculations; (d) the revDSD-PBEP86 revision of the DSD-PBEP86 double hybrid represents an improvement over the original, even though transition metals were not involved in its parametrization; and (e) DSD-SCAN and DOD-SCAN show comparable efficiency. Most tested (meta)-GGA and hybrid density functionals perform better for open-shell than for closed-shell complexes; this is not the case for the double hybrids considered.
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Affiliation(s)
- Irena Efremenko
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Jan M L Martin
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, 7610001 Rehovot, Israel
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5
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Maurer LR, Bursch M, Grimme S, Hansen A. Assessing Density Functional Theory for Chemically Relevant Open-Shell Transition Metal Reactions. J Chem Theory Comput 2021; 17:6134-6151. [PMID: 34546754 DOI: 10.1021/acs.jctc.1c00659] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Due to the principle lack of systematic improvement possibilities of density functional theory, careful assessment of the performance of density functional approximations (DFAs) on well-designed benchmark sets, for example, for reaction energies and barrier heights, is crucial. While main-group chemistry is well covered by several available sets, benchmark data for transition metal chemistry is sparse. This is especially the case for larger, chemically relevant molecules. Addressing this issue, we recently introduced the MOR41 benchmark which covers chemically relevant reactions of closed-shell complexes. In this work, we extend these efforts to single-reference open-shell systems and introduce the "reactions of open-shell single-reference transition metal complexes" (ROST61) benchmark set. ROST61 includes accurate coupled-cluster reference values for 61 reaction energies with a mean reaction energy of -42.8 kcal mol-1. Complexes with 13-93 atoms covering 20 d-block elements are included, but due to the restriction to single-reference open-shell systems, important elements such as iron or platinum could not be taken into account, or only to a small extent. We assess the performance of 31 DFAs in combination with three London dispersion (LD) correction schemes. Further, DFT-based composite methods, MP2, and a few semiempirical quantum chemical methods are evaluated. Consistent with the results for the MOR41 closed-shell benchmark, we find that the ordering of DFAs according to Jacob's ladder is preserved and that adding an LD correction is crucial, clearly improving almost all tested methods. The recently introduced r2SCAN-3c composite method stands out with a remarkable mean absolute deviation (MAD) of only 2.9 kcal mol-1, which is surpassed only by hybrid DFAs with low amounts of Fock exchange (e.g., 2.3 kcal mol-1 for TPSS0-D4/def2-QZVPP) and double-hybrid (DH) DFAs but at a significantly higher computational cost. The lowest MAD of only 1.6 kcal mol-1 is obtained with the DH DFA PWPB95-D4 in the def2-QZVPP basis set approaching the estimated accuracy of the reference method. Overall, the ROST61 set adds important reference data to a sparsely sampled but practically relevant area of chemistry. At this point, it provides valuable orientation for the application and development of new DFAs and electronic structure methods in general.
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Affiliation(s)
- Leonard R Maurer
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115 Bonn, Germany
| | - Markus Bursch
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115 Bonn, Germany
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115 Bonn, Germany
| | - Andreas Hansen
- Mulliken Center for Theoretical Chemistry, Institute for Physical and Theoretical Chemistry, University of Bonn, Beringstr. 4, 53115 Bonn, Germany
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6
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Santra G, Semidalas E, Martin JML. Surprisingly Good Performance of XYG3 Family Functionals Using a Scaled KS-MP3 Correlation. J Phys Chem Lett 2021; 12:9368-9376. [PMID: 34550706 DOI: 10.1021/acs.jpclett.1c02838] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
By adding a GLPT3 (third-order Görling-Levy perturbation theory, or KS-MP3) term E3 to the XYG7 form for a double hybrid, we are able to bring down WTMAD2 (weighted total mean absolute deviation) for the very large and chemically diverse GMTKN55 benchmark to an unprecedented 1.17 kcal/mol, competitive with much costlier composite wave function ab initio approaches. Intriguingly, (a) the introduction of E3 makes an empirical dispersion correction redundant; (b) generalized gradient approximation (GGA) or meta-GGA semilocal correlation functionals offer no advantage over the local density approximation (LDA) in this framework; (c) if a dispersion correction is retained, then simple Slater exchange leads to no significant loss in accuracy. It is possible to create a six-parameter functional with WTMAD2 = 1.42 that has no post-LDA density functional theory components and no dispersion correction in the final energy.
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Affiliation(s)
- Golokesh Santra
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, 7610001 Reḥovot, Israel
| | - Emmanouil Semidalas
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, 7610001 Reḥovot, Israel
| | - Jan M L Martin
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, 7610001 Reḥovot, Israel
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7
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Bursch M, Hansen A, Pracht P, Kohn JT, Grimme S. Theoretical study on conformational energies of transition metal complexes. Phys Chem Chem Phys 2021; 23:287-299. [PMID: 33336657 DOI: 10.1039/d0cp04696e] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Conformational energies are an important chemical property for which a performance assessment of theoretical methods is mandatory. Existing benchmark sets are often limited to biochemical or main group element containing molecules, while organometallic systems are generally less studied. A key problem herein is to routinely generate conformers for these molecules due to their complexity and manifold of possible coordination patterns. In this study we used our recently published CREST protocol [Pracht et al., Phys. Chem. Chem. Phys., 2020, 22, 7169-7192] to generate conformer ensembles for a variety of 40 challenging transition metal containing molecules, which were then used to form a comprehensive conformational energy benchmark set termed TMCONF40. Several low-cost semiempirical, density functional theory (DFT) and force-field methods were compared to high level DLPNO-CCSD(T1) and double-hybrid DFT reference values. Close attention was paid to the energetic ordering of the conformers in the statistical evaluation. With respect to the double-hybrid references, both tested low-cost composite DFT methods produce high Pearson correlation coefficients of rp,mean,B97-3c//B97-3c = 0.922 and rp,mean,PBEh-3c//B97-3c = 0.890, with mean absolute deviations close to or below 1 kcal mol-1. This good performance also holds for a comparison to DLPNO-CCSD(T1) reference energies for a smaller subset termed TMCONF5. Based on DFT geometries, the GFNn-xTB methods yield reasonable Pearson correlation coefficients of rp,mean,GFN1-xTB//B97-3c = 0.617 (MADmean = 2.15 kcal mol-1) and rp,mean,GFN2-xTB//B97-3c = 0.567 (MADmean = 2.68 kcal mol-1), outperforming the widely used PMx methods on the TMCONF40 test set. Employing the low-cost composite DFT method B97-3c on GFN2-xTB geometries yields an slightly improved correlation of rp,mean,B97-3c//GFN2-xTB = 0.632. Furthermore, for 68% of the investigated complexes at least one low-energy conformer was found that is more stable than the respective crystal structure conformation, which signals the importance of conformational studies. General recommendations for the application of the CREST protocol and DFT methods for transition metal conformational energies are given.
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Affiliation(s)
- Markus Bursch
- Mulliken Center for Theoretical Chemistry, Universität Bonn, Beringstr. 4, 53115 Bonn, Germany.
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8
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Sylvetsky N, Banerjee A, Alonso M, Martin JML. Performance of Localized Coupled Cluster Methods in a Moderately Strong Correlation Regime: Hückel-Möbius Interconversions in Expanded Porphyrins. J Chem Theory Comput 2020; 16:3641-3653. [PMID: 32338891 PMCID: PMC7304861 DOI: 10.1021/acs.jctc.0c00297] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
![]()
Localized
orbital coupled cluster theory has recently emerged as
a nonempirical alternative to DFT for large systems. Intuitively,
one might expect such methods to perform less well for highly delocalized
systems. In the present work, we apply both canonical CCSD(T) approximations
and a variety of localized approximations to a set of flexible expanded
porphyrins—macrocycles that can switch between Hückel,
figure-eight, and Möbius topologies under external stimuli.
Both minima and isomerization transition states are considered. We
find that Möbius(-like) structures have much stronger static
correlation character than the remaining structures, and that this
causes significant errors in DLPNO-CCSD(T) and even DLPNO-CCSD(T1) approaches, unless TightPNO cutoffs are employed. If sub-kcal
mol–1 accuracy with respect to canonical relative
energies is required even for Möbius-type systems (or other
systems plagued by strong static correlation), then Nagy and Kallay’s
LNO-CCSD(T) method with “tight” settings is the suitable
localized approach. We propose the present POLYPYR21 data set as a
benchmark for localized orbital methods or, more broadly, for the
ability of lower-level methods to handle energetics with strongly
varying degrees of static correlation.
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Affiliation(s)
- Nitai Sylvetsky
- Department of Organic Chemistry, Weizmann Institute of Science, 76100 Reḥovot, Israel
| | - Ambar Banerjee
- Department of Organic Chemistry, Weizmann Institute of Science, 76100 Reḥovot, Israel
| | - Mercedes Alonso
- Department of General Chemistry (ALGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium
| | - Jan M L Martin
- Department of Organic Chemistry, Weizmann Institute of Science, 76100 Reḥovot, Israel
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9
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Woller T, Banerjee A, Sylvetsky N, Santra G, Deraet X, De Proft F, Martin JML, Alonso M. Performance of Electronic Structure Methods for the Description of Hückel-Möbius Interconversions in Extended π-Systems. J Phys Chem A 2020; 124:2380-2397. [PMID: 32093467 PMCID: PMC7307915 DOI: 10.1021/acs.jpca.9b10880] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 02/21/2020] [Indexed: 12/25/2022]
Abstract
Expanded porphyrins provide a versatile route to molecular switching devices due to their ability to shift between several π-conjugation topologies encoding distinct properties. DFT remains the workhorse for modeling such extended macrocycles, when taking into account their size and huge conformational flexibility. Nevertheless, the stability of Hückel and Möbius conformers depends on a complex interplay of different factors, such as hydrogen bonding, π···π stacking, steric effects, ring strain, and electron delocalization. As a consequence, the selection of an exchange-correlation functional for describing the energy profile of topological switches is very difficult. For these reasons, we have examined the performance of a variety of wave function methods and density functionals for describing the thermochemistry and kinetics of topology interconversions across a wide range of macrocycles. Especially for hexa- and heptaphyrins, the Möbius structures have a stronger degree of static correlation than the Hückel and twisted-Hückel structures, and as a result the relative energies of singly twisted structures are a challenging test for electronic structure methods. Comparison of limited orbital space full CI calculations with CCSD(T) calculations within the same active spaces shows that post-CCSD(T) correlation contributions to relative energies are very minor. At the same time, relative energies are weakly sensitive to further basis set expansion, as proven by the minor energy differences between the extrapolated MP2/CBS energies estimated from cc-pV{T,Q}Z, diffuse-augmented heavy-aug-cc-pV{T,Q}Z and explicitly correlated MP2-F12/cc-pVDZ-F12 calculations. Hence, our CCSD(T) reference values are reasonably well-converged in both 1-particle and n-particle spaces. While conventional MP2 and MP3 yield very poor results, SCS-MP2 and particularly SOS-MP2 and SCS-MP3 agree to better than 1 kcal mol-1 with the CCSD(T) relative energies. Regarding DFT methods, the range-separated double hybrids, such as ωB97M(2) and B2GP-PLYP, outperform other functionals with RMSDs of 0.6 and 0.8 kcal mol-1, respectively. While the original DSD-PBEP86 double hybrid performs fairly poorly for these extended π-systems, the errors drop down to 1.9 kcal mol-1 for the revised revDOD-PBEP86-NL, which eliminates the same-spin correlation energy. Minnesota meta-GGA functionals with high fractions of exact exchange (M06-2X and M08-HX) also perform reasonably well, outperforming more robust and significantly less empirically parametrized functionals like SCAN0-D3.
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Affiliation(s)
- Tatiana Woller
- Department
of General Chemistry (ALGC), Faculty of Science and Bio-engineering
Sciences, Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium
- Laboratoire
de Chimie Théorique (LCT), Sorbonne
Université, CNRS, F-75005 Paris, France
| | - Ambar Banerjee
- Department
of Organic Chemistry, Weizmann Institute
of Science, 76100 Reḥovot, Israel
| | - Nitai Sylvetsky
- Department
of Organic Chemistry, Weizmann Institute
of Science, 76100 Reḥovot, Israel
| | - Golokesh Santra
- Department
of Organic Chemistry, Weizmann Institute
of Science, 76100 Reḥovot, Israel
| | - Xavier Deraet
- Department
of General Chemistry (ALGC), Faculty of Science and Bio-engineering
Sciences, Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium
| | - Frank De Proft
- Department
of General Chemistry (ALGC), Faculty of Science and Bio-engineering
Sciences, Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium
| | - Jan M. L. Martin
- Department
of Organic Chemistry, Weizmann Institute
of Science, 76100 Reḥovot, Israel
| | - Mercedes Alonso
- Department
of General Chemistry (ALGC), Faculty of Science and Bio-engineering
Sciences, Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium
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10
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Santra G, Sylvetsky N, Martin JML. Minimally Empirical Double-Hybrid Functionals Trained against the GMTKN55 Database: revDSD-PBEP86-D4, revDOD-PBE-D4, and DOD-SCAN-D4. J Phys Chem A 2019; 123:5129-5143. [PMID: 31136709 PMCID: PMC9479158 DOI: 10.1021/acs.jpca.9b03157] [Citation(s) in RCA: 223] [Impact Index Per Article: 44.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
![]()
We
present a family of minimally empirical double-hybrid DFT functionals
parametrized against the very large and diverse GMTKN55 benchmark.
The very recently proposed ωB97M(2) empirical double hybrid
(with 16 adjustable parameters) has the lowest WTMAD2 (weighted mean
absolute deviation over GMTKN55) ever reported at 2.19 kcal/mol. However,
refits of the DSD-BLYP and DSD-PBEP86 spin-component-scaled, dispersion-corrected
double hybrids can achieve WTMAD2 values as low as 2.33 with the very
recent D4 dispersion correction (2.42 kcal/mol with the D3(BJ) dispersion
term) using just a handful of adjustable parameters. If we use full
DFT correlation in the initial orbital evaluation, the xrevDSD-PBEP86-D4
functional reaches WTMAD2 = 2.23 kcal/mol, statistically indistinguishable
from ωB97M(2) but using just four nonarbitrary adjustable parameters
(and three semiarbitrary ones). The changes from the original DSD
parametrizations are primarily due to noncovalent interaction energies
for large systems, which were undersampled in the original parametrization
set. With the new parametrization, same-spin correlation can be eliminated
at minimal cost in performance, which permits revDOD-PBEP86-D4 and
revDOD-PBE-D4 functionals that scale as N4 or even N3 with the size of the system.
Dependence of WTMAD2 for DSD functionals on the percentage of HF exchange
is roughly quadratic; it is sufficiently weak that any reasonable
value in the 64% to 72% range can be chosen semiarbitrarily. DSD-SCAN
and DOD-SCAN double hybrids involving the SCAN nonempirical meta-GGA
as the semilocal component have also been considered and offer a good
alternative if one wishes to eliminate either the empirical dispersion
correction or the same-spin correlation component. noDispSD-SCAN66
achieves WTMAD2 = 3.0 kcal/mol, compared to 2.7 kcal/mol for DOD-SCAN66-D4.
However, the best performance without dispersion corrections (WTMAD2
= 2.8 kcal/mol) is reached by revωB97X-2, a slight reparametrization
of the Chai–Head-Gordon range-separated double hybrid. Finally,
in the context of double-hybrid functionals, the very recent D4 dispersion
correction is clearly superior over D3(BJ).
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Affiliation(s)
- Golokesh Santra
- Department of Organic Chemistry, Weizmann Institute of Science, 7610001 Reḥovot, Israel
| | - Nitai Sylvetsky
- Department of Organic Chemistry, Weizmann Institute of Science, 7610001 Reḥovot, Israel
| | - Jan M. L. Martin
- Department of Organic Chemistry, Weizmann Institute of Science, 7610001 Reḥovot, Israel
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