64 citations · 337 across the 17 of their papers we have counts for
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Post-CCSD(T) corrections in the S66 noncovalent interactions benchmark
Emmanouil Semidalas, A. Daniel Boese, Jan M. L. Martin
For noncovalent interactions, it is generally assumed that CCSD(T) is nearly the exact solution within the 1-particle basis set. For the S66 noncovalent interactions benchmark, we…
How `Nonvariational' Are Approximate Coupled Cluster Methods In Practice?
Jan M. L. Martin, Emmanouil Semidalas
While limited coupled cluster theory is \textit{formally} nonvariational, it is not broadly appreciated whether this is a major issue \textit{in practice}. We carried out a detaile…
Does basis set superposition error significantly affect post-CCSD(T) corrections?
Vladimir Fishman, Emmanouil Semidalas, Margarita Shepelenko +1
We have investigated the title question for both a subset of the W4-11 total atomization energies benchmark, and for the A24x8 noncovalent interactions benchmark. Overall, counterp…
Basis set extrapolation from the vanishing counterpoise correction condition
Vladimir Fishman, Emmanouil Semidalas, Jan M. L. Martin
Basis set extrapolations are typically rationalized either from analytical arguments involving the partial-wave or principal expansions of the correlation energy in helium-like sys…
W4: leveraging coupled cluster for accurate computational thermochemistry approaches
Emmanouil Semidalas, Amir Karton, Jan M. L. Martin
High-accuracy composite wavefunction methods like Weizmann-4 (W4) theory, high-accuracy extrapolated \textit{ab initio} thermochemistry (HEAT), and Feller-Peterson-Dixon (FPD) enab…
Can G4-like Composite Ab Initio Methods Accurately Predict Vibrational Harmonic Frequencies?
Emmanouil Semdalas, Jan M. L. Martin
Minimally empirical G4-like composite wavefunction theories [E. Semidalas and J. M. L. Martin, \textit{J. Chem. Theory Comput.} {\bf 16}, 4238-4255 and 7507-7524 (2020)] trained ag…
Post-CCSD(T) corrections to bond distances and vibrational frequencies: the power of
Maciej Spiegel, Emmanouil Semidalas, Jan M. L. Martin +2
The importance of post-CCSD(T) corrections as high as CCSDTQ56 for ground-state spectroscopic constants (, , , and ) has been surveyed for a sample of two do…
Is valence CCSD(T) enough for the binding of water clusters? The isomers of (HO) and (HO) as a case study
Golokesh Santra, Margarita Shepelenko, Emmanouil Semidalas +1
Benchmark calculations on noncovalent interactions typically exclude correlation effects beyond valence CCSD(T) owing to their steep computational cost scaling. In this work, we co…
S66x8 Noncovalent Interactions Revisited: New Benchmark and Performance of Composite Localized Coupled-Cluster Methods
Golokesh Santra, Emmanouil Semidalas, Nisha Mehta +2
The S66x8 noncovalent interactions benchmark has been re-evaluated at the "sterling silver" level, using explicitly correlated MP2-F12 near the complete basis set limit, CCSD(F12*)…
Automatic generation of complementary auxiliary basis sets (CABS) for explicitly correlated methods
Emmanouil Semidalas, Jan M. L. Martin
Explicitly correlated calculations, aside from the orbital basis set, typically require three auxiliary basis sets: JK (Coulomb-exchange fitting), RI-MP2 (resolution of the identit…
The S66 Noncovalent Interaction Benchmark Re-examined: Composite Localized Coupled Cluster Approaches
Emmanouil Semidalas, Golokesh Santra, Nisha Mehta +1
The S66 non-covalent interactions are studied through localized coupled-cluster methods and general LNO-CCSD(T)-based composite schemes. Very small RMS deviations (\leq 0.05 kcal/m…
An Exchange-Based Diagnostic for Static Correlation
Jan M. L. Martin, Golokesh Santra, Emmanouil Semidalas
We propose here a DFT-based diagnostic for static correlation %TAEX[TPSS@HF - HF] which effectively measures how different the DFT and HF exchange energies for a given HF density a…
The MOBH35 metal-organic barrier heights reconsidered: performance of local-orbital coupled cluster approaches in different static correlation regimes
Emmanouil Semidalas, Jan M. L. Martin
We have revisited the MOBH35 (Metal-Organic Barrier Heights, 35 reactions) benchmark [Iron, M. A.; Janes, T. J. Phys. Chem. A 2019, 123 (17), 3761-3781; ibid. 2019, 123, 6379-6380]…
Surprisingly Good Performance of XYG3 Family Functionals Using Scaled KS-MP3 Correlation
Golokesh Santra, Emmanouil Semidalas, Jan M. L. Martin
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 abso…
Exploring Avenues Beyond Revised DSD Functionals: II. Random-Phase Approximation and scaled MP3 corrections
Golokesh Santra, Emmanouil Semidalas, Jan M. L. Martin
For revDSD double hybrids, the Görling-Levy second-order perturbation theory component is an Achilles' Heel when applied to systems with significant near-degeneracy ("static") corr…
Canonical and DLPNO-based composite wavefunction methods parametrized against large and chemically diverse training sets. 2. Correlation consistent basis sets, core-valence correlation, and F12 alternatives
Emmanouil Semidalas, Jan M. L. Martin
A hierarchy of wavefunction composite methods (cWFT), based on G4- type cWFT methods available for elements H through Rn, was recently reported by Semidalas and Martin [J. Chem. Th…
Canonical and DLPNO-based G4(MP2)XK-inspired composite wavefunction methods parametrized against large and chemically diverse training sets: Are they more accurate and/or robust than double hybrid DFT?
Emmanouil Semidalas, Jan M. L. Martin
The large and chemically diverse GMTKN55 benchmark was used as a training set for parametrizing composite wave function thermochemistry protocols akin to G4(MP2)XK theory (Chan et…