Exploring the Accuracy of a Low Scaling Similarity Transformed Equation of Motion Method for Vertical Excitation Energies

Dutta, Achintya Kumar; Nooijen, Marcel; Neese, Frank; Izsák, Róbert

doi:10.1021/acs.jctc.7b00802

Cited by 109 publications

(184 citation statements)

References 109 publications

Supporting

Mentioning

168

Contrasting

Order By: Relevance

“…These three highly-symmetric systems allow to directly perform CCSDT/aVTZ calculations for singlet states without the need of basis set extrapolations. Benzene was studied many times before, 23,[25][26][27]34,66,69,72,120,136,183,[212][213][214][215][216][217][218][219][220] and we report in Tables 7 and S7 estimates obtained for five singlet and three triplet ES, all characterized by %T 1 exceeding 90% except for the lowest singlet (86%). As one can see, the two CC approaches are again yielding very consistent transition energies with variations in the 0.00-0.03 eV range.…”

Section: Benzene Pyrazine and Tetrazinementioning

confidence: 93%

“…23,[25][26][27]30,66,69,104,120,160,183,212,213,239,241,[244][245][246][247] Our results for pyridazine and pyridine are gathered in Tables 9 and S9. For the former compound, the available wavefunction 23,[25][26][27]30,66,69,212,213,239,245 focussed on singlet transitions, at the exception of rather old MRCI, 239 and CASPT2 investigations. 245 Again, the %T 1 values are larger than 85% (95%) for the singlet (triplet) transitions, and the only state for which there is a variation larger than 0.03 eV between the CC3/aVDZ and CCSDT/aVDZ energies is the 3 B 2 (π → π ) transition.…”

Section: Pyridazine Pyridine Pyrimidine and Triazinementioning

confidence: 99%

“…Interestingly, beyond the popular twenty-year old reference measurements, 239,248 there is a very recent experimental EEL analysis for pyridazine, 240 Pyridine, the hallmark heterocycle, has been more scrutinized than pyridazine and many wavefunction approaches have been applied to estimate its ES energies. 23,[25][26][27]30,66,69,104,160,183,212,213,241,246,247 Besides, two detailed EEL experiments are also available for pyridine. 242,243 The general trends described above for other six-membered cycles do pertain with: i) large %T 1 values and consistency between CC3 and CCSDT estimates for all transitions listed in Table 9; ii) small basis set effects beyond aVTZ even for the Rydberg transitions; iii) qualitative agreement with past CC results; iv) NEVPT2 transitions energies that are, on average, larger than their CC counterparts; and v) same ES ranking as in the most recent measurements.…”

Section: Pyridazine Pyridine Pyrimidine and Triazinementioning

confidence: 99%

“…Because the former derivative can be viewed as the smallest model of DNA bases, previous theoretical 23,[25][26][27]30,66,69,160,183,212,213,218,[249][250][251] and experimental 234,252,253 studies are rather extensive. For triazine, which belongs to a non-abelian point group, theoretical studies are scarcer, 23,[25][26][27]30,66,69,212,213,244,254,255 especially for the triplets, 244,254,255 whereas the experimental data are also limited. 234,244 As in pyridazine and pyridine, all the ES listed in Table 10 show %T 1 values larger than 85% for singlets and 95% for triplets, so that CC3 and CCSDT are highly coherent, except maybe for the 3 A 1 (π → π ) transitions in pyrimidine.…”

Section: Pyridazine Pyridine Pyrimidine and Triazinementioning

confidence: 99%

See 3 more Smart Citations

A Mountaineering Strategy to Excited States: Highly-Accurate Energies and Benchmarks for Medium Size Molecules

Loos

Lipparini²,

Boggio‐Pasqua³

et al. 2019

Preprint

View full text Add to dashboard Cite

Following our previous work focussing on compounds containing up to 3 non-hydrogen atoms [J. Chem. Theory Comput. 14 (2018) [4360][4361][4362][4363][4364][4365][4366][4367][4368][4369][4370][4371][4372][4373][4374][4375][4376][4377][4378][4379], we present here highly-accurate vertical transition energies obtained for 27 molecules encompassing 4, 5, and 6 non-hydrogen atoms: equation-of-motion coupled cluster theory up to the highest technically possible excitation order for these systems (CC3, EOM-CCSDT, and EOM-CCSDTQ), selected configuration interaction 1 arXiv:1912.04173v2 [physics.chem-ph] 31 Jan 2020 (SCI) calculations (with tens of millions of determinants in the reference space), as well as the multiconfigurational n-electron valence state perturbation theory (NEVPT2) method. All these approaches are applied in combination with diffuse-containing atomic basis sets. For all transitions, we report at least CC3/aug-cc-pVQZ vertical excitation energies as well as CC3/aug-cc-pVTZ oscillator strengths for each dipole-allowed transition. We show that CC3 almost systematically delivers transition energies in agreement with higher-level methods with a typical deviation of ±0.04 eV, except for transitions with a dominant double excitation character where the error is much larger. The present contribution gathers a large, diverse and accurate set of more than 200 highly-accurate transition energies for states of various natures (valence, Rydberg, singlet, triplet, n → π , π → π , . . . ). We use this series of theoretical best estimates to benchmark a series of popular methods for excited state calculations: CIS(D), ADC(2), CC2, STEOM-CCSD, EOM-CCSD, CCSDR(3), CCSDT-3, CC3, as well as NEVPT2. The results of these benchmarks are compared to the available literature data.Although these conclusions agree well with earlier studies, 69-71 they obviously only hold for single excitations, i.e., transitions with %T 1 in the 80-100% range. Therefore, we also recently proposed a set of 20 TBE for transitions exhibiting a significant double-excitation character (i.e., with %T 1 typically below 80%). 72 Unsurprisingly, our results clearly evidenced that the error in CC methods is intimately related to the %T 1 value. For example, for the ES with a significant yet not dominant double excitation character [such as the infamous A g ES of butadiene (%T 1 = 75%)] CC methods including triples deliver rather accurate estimates (MAE of 0.11 eV with CC3 and 0.06 eV with CCSDT), surprisingly outperforming second-order multi-reference schemes such as CASPT2 or the generally robust n-electron valence state perturbation theory (NEVPT2). In contrast, for ES with a dominant double excitation character, e.g., the low-lying (n, n) → (π , π ) excitation in nitrosomethane (%T 1 = 2%), single-reference methods (not including quadruples) have been found to be unsuitable with MAEs of 0.86 and 0.42 eV for CC3 and CCSDT, respectively. In this case, multiconfigurational methods are in practice required to obtain accurate results. 72 A clear limit of ...

show abstract

Section: Benzene Pyrazine and Tetrazinementioning

confidence: 93%

Section: Pyridazine Pyridine Pyrimidine and Triazinementioning

confidence: 99%

Section: Pyridazine Pyridine Pyrimidine and Triazinementioning

confidence: 99%

Section: Pyridazine Pyridine Pyrimidine and Triazinementioning

confidence: 99%

See 2 more Smart Citations

A Mountaineering Strategy to Excited States: Highly-Accurate Energies and Benchmarks for Medium Size Molecules

Loos

Lipparini²,

Boggio‐Pasqua³

et al. 2019

Preprint

View full text Add to dashboard Cite

show abstract

“…[2][3][4] In these studies the methods tested included several DFT functionals, CIS and SAC-CI. The most systematic study has been published by Dutta et al 7 which includes six states of two systems, and results for various Coupled-Cluster (CC) ansätze are presented. The importance of systematic study is emphasized by the fact that severe inconsistency of certain popular methods in the description of Rydberg-type states 8,9 poses a warning that not all techniques may be well suited for CT states, either.…”

Section: Introductionmentioning

confidence: 99%

A New Benchmark Set for Excitation Energy of Charge Transfer States: Systematic Investigation of Coupled-Cluster Type Methods

Kozma¹,

Tajti²,

Démoulin³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

There are numerous publications on benchmarking quantum chemistry methods for excited states. These studies rarely include Charge Transfer (CT) states although many interesting phenomena in e.g. biochemistry and material physics involve transfer of electron between fragments of the system. Therefore, it is timely to test the accuracy of quantum chemical methods for CT states, as well. In this study we first suggest a set benchmark systems consisting of dimers having low-energy CT states. On this set, the excitation energy has been calculated with coupled cluster methods including triple excitations (CC3, CCSDT-3, CCSD(T)(a)* ), as well as with methods including full or approximate doubles (CCSD, STEOM-CCSD, CC2, ADC(2), EOM-CCSD(2)). The results show that the popular CC2 and ADC(2) methods are much more inaccurate for CT states than for valence states. On the other hand, CCSD seems to have similar systematic overestimation of the excitation energies for both valence and CT states.Concerning triples methods, the new CCSD(T)(a)* method including non-iterative triple excitations preforms very well for all type of states, delivering essentially CCSDT quality results.

show abstract

Interactions of Solvated Electrons with Nucleobases: The Effect of Base Pairing

2020

Self Cite

View full text Add to dashboard Cite

We have investigated the effect of base pairing on the electron attachment to nucleobases in bulk water, taking the guanineÀ cytosine (GC) base pair as a test case. The presence of the complementary base reinforces the stabilization effect provided by water and preferentially stabilizes the anion by hydrogen bonding. The electron attachment in bulk-solvated GC happens through a doorway mechanism, where the initial electron attached state is water bound, and it subsequently gets converted to a GC bound state. The additional electron in the final GC bound state is localized on the cytosine, similar to that in the gas phase. The transfer of the electron from the initial water-bound state to the final GC bound state happens due to the mixing of electronic and nuclear degrees of freedom and takes place at a picosecond time scale.[a] Dr.

show abstract

Exploring the Accuracy of a Low Scaling Similarity Transformed Equation of Motion Method for Vertical Excitation Energies

Cited by 109 publications

References 109 publications

A Mountaineering Strategy to Excited States: Highly-Accurate Energies and Benchmarks for Medium Size Molecules

A Mountaineering Strategy to Excited States: Highly-Accurate Energies and Benchmarks for Medium Size Molecules

A New Benchmark Set for Excitation Energy of Charge Transfer States: Systematic Investigation of Coupled-Cluster Type Methods

Interactions of Solvated Electrons with Nucleobases: The Effect of Base Pairing

Contact Info

Product

Resources

About