scholarly journals Benchmarking London dispersion corrected density functional theory for noncovalent ion-pi interactions

2021 ◽  
Author(s):  
Sebastian Spicher ◽  
Eike Caldeweyher ◽  
Andreas Hansen ◽  
Stefan Grimme
Keyword(s):  
Electrostatic Interactions ◽  
Density Functional ◽  
Functional Performance ◽  
Dispersion Model ◽  
Coupled Cluster ◽  
Interaction Energies ◽  
Binding Motifs ◽  
Hybrid Functionals ◽  
London Dispersion ◽  
Pi Interactions

<p>The strongly attractive noncovalent interactions of charged atoms or molecules with p-systems are important binding motifs in many chemical and biological systems. These so-called ion-pi interactions play a major role in enzymes, molecular recognition, and for the structure of proteins. In this work, a molecular test set termed IONPI19 is compiled for inter- and intramolecular ion-pi interactions, which is well balanced between anionic and cationic systems. The IONPI19 set includes interaction energies of significantly larger molecules (up to 133 atoms) than in other ion-pi test sets and covers a broad range of binding motifs. Accurate (local) coupled cluster values are provided as reference. Overall, 18 density functional approximations, including seven (meta-)GGAs, seven hybrid functionals, and four double hybrid functionals combined with three different London dispersion corrections, are benchmarked for interaction energies. DFT results are further compared to wave function based methods such as MP2 and dispersion corrected Hartree-Fock. Also the performance</p><p>of semiempirical QM methods such as the GFNn-xTB and PMx family of methods is tested. It is shown that dispersion-uncorrected DFT underestimates ion-pi interactions significantly, even though electrostatic interactions dominate the overall binding. Accordingly, the new charge dependent D4 dispersion model is found to be consistently better than the standard D3 correction. Furthermore, the functional performance trend along Jacob’s ladder is generally obeyed and the reduction of the self-interaction error leads to an improvement of (double) hybrid functionals over (meta-)GGAs, even though the effect of the SIE is smaller than expected. Overall, the double hybrids PWPB95-D4/QZ and revDSD-PBEP86-D4/QZ turned out to be the most reliable among all assessed methods in predicting ion-pi interactions, which opens up new perspectives for systems where coupled cluster calculations are no longer computationally feasible.</p>

scholarly journals Benchmarking London dispersion corrected density functional theory for noncovalent ion-pi interactions

2021 ◽  
Author(s):  
Sebastian Spicher ◽  
Eike Caldeweyher ◽  
Andreas Hansen ◽  
Stefan Grimme
Keyword(s):  
Electrostatic Interactions ◽  
Density Functional ◽  
Functional Performance ◽  
Dispersion Model ◽  
Coupled Cluster ◽  
Interaction Energies ◽  
Binding Motifs ◽  
Hybrid Functionals ◽  
London Dispersion ◽  
Pi Interactions

<p>The strongly attractive noncovalent interactions of charged atoms or molecules with p-systems are important binding motifs in many chemical and biological systems. These so-called ion-pi interactions play a major role in enzymes, molecular recognition, and for the structure of proteins. In this work, a molecular test set termed IONPI19 is compiled for inter- and intramolecular ion-pi interactions, which is well balanced between anionic and cationic systems. The IONPI19 set includes interaction energies of significantly larger molecules (up to 133 atoms) than in other ion-pi test sets and covers a broad range of binding motifs. Accurate (local) coupled cluster values are provided as reference. Overall, 18 density functional approximations, including seven (meta-)GGAs, seven hybrid functionals, and four double hybrid functionals combined with three different London dispersion corrections, are benchmarked for interaction energies. DFT results are further compared to wave function based methods such as MP2 and dispersion corrected Hartree-Fock. Also the performance</p><p>of semiempirical QM methods such as the GFNn-xTB and PMx family of methods is tested. It is shown that dispersion-uncorrected DFT underestimates ion-pi interactions significantly, even though electrostatic interactions dominate the overall binding. Accordingly, the new charge dependent D4 dispersion model is found to be consistently better than the standard D3 correction. Furthermore, the functional performance trend along Jacob’s ladder is generally obeyed and the reduction of the self-interaction error leads to an improvement of (double) hybrid functionals over (meta-)GGAs, even though the effect of the SIE is smaller than expected. Overall, the double hybrids PWPB95-D4/QZ and revDSD-PBEP86-D4/QZ turned out to be the most reliable among all assessed methods in predicting ion-pi interactions, which opens up new perspectives for systems where coupled cluster calculations are no longer computationally feasible.</p>

scholarly journals Application of London Dispersion Corrected Density Functional Theory for Non-Covalent Ion-π Interactions

2020 ◽  
Author(s):  
Eike Caldeweyher ◽  
Sebastian Spicher ◽  
Andreas Hansen ◽  
Stefan Grimme
Keyword(s):  
Electrostatic Interactions ◽  
Density Functional ◽  
Dispersion Model ◽  
Computational Cost ◽  
Coupled Cluster ◽  
Dispersion Interactions ◽  
Field Methods ◽  
Approximate Methods ◽  
London Dispersion ◽  
Pi Interactions

<p>The strongly attractive non-covalent interactions of charged atoms or molecules with pi-systems are important bonding motifs in many chemical and biological systems. These so-called ion-pi interactions play a major role in enzymes, molecular recognition, and for the structure of proteins. To model ion-pi interactions with DFT, it is crucial</p><p>to include London dispersion interactions, whose importance for ion-pi interactions is often underestimated. In this work, several dispersion-corrected DFT methods are evaluated for inter- and intramolecular anionic- and anion-pi interactions in larger and practically relevant molecules. We compare the DFT results with MP2, while highly</p><p>accurate (local) coupled cluster values are provided as reference. The latter can also be a great help in the development and validation of approximate methods. We demonstrate that dispersion-uncorrected DFT underestimates ion-pi interactions significantly, even though electrostatic interactions dominate the overall binding. Accordingly, the</p><p>new charge dependent D4 dispersion model is found to be consistently better than the standard D3 correction. Dispersion-corrected DFT clearly outperforms MP2/CBS whereby the best performers come close to the accuracy limit of the reference values at considerably smaller computational cost. Due to its low cost, D4 can be combined</p><p>very well with semi-empirical QM and force field methods, which is important in the development of more accurate methods for modeling large (bio)chemical systems (e.g. proteins). Another important aspect in modeling these charged systems with DFT is the self-interaction error (SIE). However, we do not find it to constitute a significant problem. Overall, the double hybrid PWPB95-D4/QZ turned out to be the most reliable among all assessed methods in predicting ion-pi interactions, which opens up new perspectives for systems where coupled cluster calculations are no longer computationally feasible.</p>

scholarly journals Application of London Dispersion Corrected Density Functional Theory for Non-Covalent Ion-π Interactions

2020 ◽  
Author(s):  
Eike Caldeweyher ◽  
Sebastian Spicher ◽  
Andreas Hansen ◽  
Stefan Grimme
Keyword(s):  
Electrostatic Interactions ◽  
Density Functional ◽  
Dispersion Model ◽  
Computational Cost ◽  
Coupled Cluster ◽  
Dispersion Interactions ◽  
Field Methods ◽  
Approximate Methods ◽  
London Dispersion ◽  
Pi Interactions

<p>The strongly attractive non-covalent interactions of charged atoms or molecules with pi-systems are important bonding motifs in many chemical and biological systems. These so-called ion-pi interactions play a major role in enzymes, molecular recognition, and for the structure of proteins. To model ion-pi interactions with DFT, it is crucial</p><p>to include London dispersion interactions, whose importance for ion-pi interactions is often underestimated. In this work, several dispersion-corrected DFT methods are evaluated for inter- and intramolecular anionic- and anion-pi interactions in larger and practically relevant molecules. We compare the DFT results with MP2, while highly</p><p>accurate (local) coupled cluster values are provided as reference. The latter can also be a great help in the development and validation of approximate methods. We demonstrate that dispersion-uncorrected DFT underestimates ion-pi interactions significantly, even though electrostatic interactions dominate the overall binding. Accordingly, the</p><p>new charge dependent D4 dispersion model is found to be consistently better than the standard D3 correction. Dispersion-corrected DFT clearly outperforms MP2/CBS whereby the best performers come close to the accuracy limit of the reference values at considerably smaller computational cost. Due to its low cost, D4 can be combined</p><p>very well with semi-empirical QM and force field methods, which is important in the development of more accurate methods for modeling large (bio)chemical systems (e.g. proteins). Another important aspect in modeling these charged systems with DFT is the self-interaction error (SIE). However, we do not find it to constitute a significant problem. Overall, the double hybrid PWPB95-D4/QZ turned out to be the most reliable among all assessed methods in predicting ion-pi interactions, which opens up new perspectives for systems where coupled cluster calculations are no longer computationally feasible.</p>

Intrinsic Stacking Interactions of Natural and Artificial Nucleobases

2019 ◽  
Author(s):  
Drew P. Harding ◽  
Laura J. Kingsley ◽  
Glen Spraggon ◽  
Steven Wheeler
Keyword(s):  
Gas Phase ◽  
Electrostatic Interactions ◽  
Density Functional ◽  
Molecular Descriptors ◽  
Stacking Interactions ◽  
Interaction Energies ◽  
Functional Theory ◽  
Binding Partner ◽  
Heavy Atoms ◽  
Wide Range

The intrinsic (gas-phase) stacking energies of natural and artificial nucleobases were explored using density functional theory (DFT) and correlated ab initio methods. Ranking the stacking strength of natural nucleobase dimers revealed a preference in binding partner similar to that seen from experiments, namely G > C > A > T > U. Decomposition of these interaction energies using symmetry-adapted perturbation theory (SAPT) showed that these dispersion dominated interactions are modulated by electrostatics. Artificial nucleobases showed a similar stacking preference for natural nucleobases and were also modulated by electrostatic interactions. A robust predictive multivariate model was developed that quantitively predicts the maximum stacking interaction between natural and a wide range of artificial nucleobases using molecular descriptors based on computed electrostatic potentials (ESPs) and the number of heavy atoms. This model should find utility in designing artificial nucleobase analogs that exhibit stacking interactions comparable to those of natural nucleobases. Further analysis of the descriptors in this model unveil the origin of superior stacking abilities of certain nucleobases, including cytosine and guanine.

Balancing DFT Interaction Energies in Charged Dimers Precursors to Organic Semiconductors

2019 ◽  
Author(s):  
Alberto Fabrizio ◽  
Riccardo Petraglia ◽  
Clemence Corminboeuf
Keyword(s):  
Organic Semiconductors ◽  
Density Functional ◽  
Radical Cations ◽  
Closed Shell ◽  
Open Shell ◽  
Binding Energies ◽  
Interaction Energies ◽  
Functional Theory ◽  
Energy Profiles ◽  
London Dispersion

Accurately describing intermolecular interactions within the framework of Kohn-Sham density functional theory (KS-DFT) has resulted in numerous benchmark databases over the past two decades. By far, the largest efforts have been spent on closed-shell, neutral dimers for which today, the interaction energies and geometries can be accurately reproduced by various combinations of dispersion-corrected density functional approximations (DFAs). In sharp contrast, charged, open-shell dimers remain a challenge as illustrated by the analysis of the OREL26rad benchmark set consisting of pi-dimer radical cations. Aside from the methodological aspect, achieving a proper description of radical cationic complexes is appealing due to their role as models for charge carriers in organic semiconductors. In the interest of providing an assessment of more realistic dimer systems, we construct a dataset of large radical cationic dimers (CryOrel) and jointly train the 19 parameters of a dispersion corrected, range-separated hybrid density functional (wB97X-dDsC), with the objective of providing the maximum balance between the treatment of long-range London dispersion and reduction of the delocalization error. These conditions are essential to obtain accurate energy profiles and binding energies of charged, open-shell dimers. Comparisons with the performance of the parent wB97X functional series and state-of-the-art wavefunction based methods are provided. <br>

The CHAL336 Benchmark Set: How Well Do Quantum-Chemical Methods Describe Chalcogen-Bonding Interactions?

2021 ◽  
Author(s):  
Nisha Mehta ◽  
Thomas Fellowes ◽  
JONATHAN WHITE ◽  
Lars Goerigk
Keyword(s):  
Density Functional ◽  
Noncovalent Interactions ◽  
Interaction Energies ◽  
Chemical Methods ◽  
Dft Methods ◽  
The Past ◽  
Quantum Chemical Methods ◽  
London Dispersion ◽  
High Level ◽  
Selection Of

<div> <div> <div> <p>We present the CHAL336 benchmark set—the most comprehensive database for the assessment of chalcogen-bonding (CB) interactions. After careful selection of suitable systems and identification of three high-level reference methods, the set comprises 336 dimers each consisting of up to 49 atoms and covers both σ- and π-hole interactions across four categories: chalcogen-chalcogen, chalcogen-π, chalcogen-halogen, and chalcogen-nitrogen interactions. In a subsequent study of DFT methods, we re- emphasize the need for using proper London-dispersion corrections when treating noncovalent interactions. We also point out that the deterioration of results and systematic overestimation of interaction energies for some dispersion-corrected DFT methods does not hint at problems with the chosen dispersion correction, but is a consequence of large density-driven errors. We conclude this work by performing the most detailed DFT benchmark study for CB interactions to date. We assess 98 variations of dispersion- corrected and -uncorrected DFT methods, and carry out a detailed analysis of 72 of them. Double-hybrid functionals are the most reliable approaches for CB interactions, and they should be used whenever computationally feasible. The best three double hybrids are SOS0-PBE0-2-D3(BJ), revDSD-PBEP86-D3(BJ), and B2NCPLYP-D3(BJ). The best hybrids in this study are ωB97M-V, PW6B95-D3(0), and PW6B95-D3(BJ). We do not recommend using any lower-rung DFT methods nor the popular B3LYP and MP2 approaches, which have been used to describe CB interactions in the past. We hope to inspire a change in computational protocols surrounding CB interactions that leads away from the commonly used, popular methods to the more robust and accurate ones recommended herein. We would also like to encourage method developers to use our set for the investigation and reduction of density-driven errors in new density functional approximations. </p> </div> </div> </div>

A Generally Applicable Atomic-Charge Dependent London Dispersion Correction Scheme

2019 ◽  
Author(s):  
Eike Caldeweyher ◽  
Sebastian Ehlert ◽  
Andreas Hansen ◽  
Hagen Neugebauer ◽  
Sebastian Spicher ◽  
...  
Keyword(s):  
Density Functional ◽  
Dispersion Model ◽  
Low Cost ◽  
Atomic Charge ◽  
Body Part ◽  
Dispersion Interactions ◽  
Dispersion Coefficients ◽  
Charge Dependence ◽  
London Dispersion ◽  
Dynamic Polarizabilities

The D4 model is presented for the accurate computation of London dispersion interactions in density functional theory approximations (DFT-D4) and generally for atomistic modeling methods. In this successor to the DFT-D3 model, the atomic coordination-dependent dipole polarizabilities are scaled based on atomic partial charges which can be taken from various sources. For this purpose, a new charge-dependent parameter-economic scaling function is designed. Classical charges are obtained from an atomic electronegativity equilibration procedure for which efficient analytical derivatives are developed. A numerical Casimir-Polder integration of the atom-in-molecule dynamic polarizabilities yields charge- and geometry-dependent dipole-dipole dispersion coefficients. Similar to the D3 model, the dynamic polarizabilities are pre-computed by time-dependent DFT and elements up to radon are covered. For a benchmark set of 1225 dispersion coefficients, the D4 model achieves an unprecedented accuracy with a mean relative deviation of 3.8% compared to 4.7% for D3. In addition to the two-body part, three-body effects are described by an Axilrod-Teller-Muto term. A common many-body dispersion expansion was extensively tested and an energy correction based on D4 polarizabilities is found to be advantageous for some larger systems. Becke-Johnson-type damping parameters for DFT-D4 are determined for more than 60 common functionals. For various energy benchmark sets DFT-D4 slightly outperforms DFT-D3. Especially for metal containing systems, the introduced charge dependence improves thermochemical properties. We suggest (DFT-)D4 as a physically improved and more sophisticated dispersion model in place of DFT-D3 for DFT calculations as well as for other low-cost approaches like semi-empirical models.<br><br>

A Generally Applicable Atomic-Charge Dependent London Dispersion Correction Scheme

2019 ◽  
Author(s):  
Eike Caldeweyher ◽  
Sebastian Ehlert ◽  
Andreas Hansen ◽  
Hagen Neugebauer ◽  
Sebastian Spicher ◽  
...  
Keyword(s):  
Density Functional ◽  
Dispersion Model ◽  
Low Cost ◽  
Atomic Charge ◽  
Body Part ◽  
Dispersion Interactions ◽  
Dispersion Coefficients ◽  
Charge Dependence ◽  
London Dispersion ◽  
Dynamic Polarizabilities

The D4 model is presented for the accurate computation of London dispersion interactions in density functional theory approximations (DFT-D4) and generally for atomistic modeling methods. In this successor to the DFT-D3 model, the atomic coordination-dependent dipole polarizabilities are scaled based on atomic partial charges which can be taken from various sources. For this purpose, a new charge-dependent parameter-economic scaling function is designed. Classical charges are obtained from an atomic electronegativity equilibration procedure for which efficient analytical derivatives are developed. A numerical Casimir-Polder integration of the atom-in-molecule dynamic polarizabilities yields charge- and geometry-dependent dipole-dipole dispersion coefficients. Similar to the D3 model, the dynamic polarizabilities are pre-computed by time-dependent DFT and elements up to radon are covered. For a benchmark set of 1225 dispersion coefficients, the D4 model achieves an unprecedented accuracy with a mean relative deviation of 3.8% compared to 4.7% for D3. In addition to the two-body part, three-body effects are described by an Axilrod-Teller-Muto term. A common many-body dispersion expansion was extensively tested and an energy correction based on D4 polarizabilities is found to be advantageous for some larger systems. Becke-Johnson-type damping parameters for DFT-D4 are determined for more than 60 common functionals. For various energy benchmark sets DFT-D4 slightly outperforms DFT-D3. Especially for metal containing systems, the introduced charge dependence improves thermochemical properties. We suggest (DFT-)D4 as a physically improved and more sophisticated dispersion model in place of DFT-D3 for DFT calculations as well as for other low-cost approaches like semi-empirical models.<br><br>

scholarly journals The effect of electronic excitation on London dispersion

2018 ◽  
Vol 96 (7) ◽  
pp. 730-737 ◽  
Author(s):  
Xibo Feng ◽  
Alberto Otero-de-la-Roza ◽  
Erin R. Johnson
Keyword(s):  
Density Functional ◽  
Electronic Excitation ◽  
Organic Dyes ◽  
Dispersion Model ◽  
Dispersion Energy ◽  
Dispersion Coefficients ◽  
Light Emitting ◽  
Molecular Dispersion ◽  
London Dispersion

Atomic and molecular dispersion coefficients can now be calculated routinely using density-functional theory. In this work, we present the first determination of how electronic excitation affects molecular C6 London dispersion coefficients from the exchange-hole dipole moment (XDM) dispersion model. Excited states are typically found to have larger dispersion coefficients than the corresponding ground states, due to their more diffuse electron densities. A particular focus is both intramolecular and intermolecular charge-transfer excitations, which have high absorbance intensities and are important in organic dyes, light-emitting diodes, and photovoltaics. In these classes of molecules, the increase in C6 for the electron-accepting moiety is largely offset by a decrease in C6 for the electron-donating moiety. As a result, the change in dispersion energy for a chromophore interacting with neighbouring molecules in the condensed phase is minimal.

scholarly journals The CHAL336 Benchmark Set: How Well Do Quantum-Chemical Methods Describe Chalcogen-Bonding Interactions?

2021 ◽  
Author(s):  
Nisha Mehta ◽  
Thomas Fellowes ◽  
JONATHAN WHITE ◽  
Lars Goerigk
Keyword(s):  
Density Functional ◽  
Noncovalent Interactions ◽  
Interaction Energies ◽  
Chemical Methods ◽  
Dft Methods ◽  
The Past ◽  
Quantum Chemical Methods ◽  
London Dispersion ◽  
High Level ◽  
Selection Of

<div> <div> <div> <p>We present the CHAL336 benchmark set—the most comprehensive database for the assessment of chalcogen-bonding (CB) interactions. After careful selection of suitable systems and identification of three high-level reference methods, the set comprises 336 dimers each consisting of up to 49 atoms and covers both σ- and π-hole interactions across four categories: chalcogen-chalcogen, chalcogen-π, chalcogen-halogen, and chalcogen-nitrogen interactions. In a subsequent study of DFT methods, we re- emphasize the need for using proper London-dispersion corrections when treating noncovalent interactions. We also point out that the deterioration of results and systematic overestimation of interaction energies for some dispersion-corrected DFT methods does not hint at problems with the chosen dispersion correction, but is a consequence of large density-driven errors. We conclude this work by performing the most detailed DFT benchmark study for CB interactions to date. We assess 98 variations of dispersion- corrected and -uncorrected DFT methods, and carry out a detailed analysis of 72 of them. Double-hybrid functionals are the most reliable approaches for CB interactions, and they should be used whenever computationally feasible. The best three double hybrids are SOS0-PBE0-2-D3(BJ), revDSD-PBEP86-D3(BJ), and B2NCPLYP-D3(BJ). The best hybrids in this study are ωB97M-V, PW6B95-D3(0), and PW6B95-D3(BJ). We do not recommend using any lower-rung DFT methods nor the popular B3LYP and MP2 approaches, which have been used to describe CB interactions in the past. We hope to inspire a change in computational protocols surrounding CB interactions that leads away from the commonly used, popular methods to the more robust and accurate ones recommended herein. We would also like to encourage method developers to use our set for the investigation and reduction of density-driven errors in new density functional approximations. </p> </div> </div> </div>

Sign in / Sign up

Export Citation Format

Share Document