Basis set converged weak interaction energies from conventional and explicitly correlated coupled-cluster approach

2013 ◽  
Vol 138 (15) ◽  
pp. 154101 ◽  
Author(s):  
Konrad Patkowski
Keyword(s):  
Weak Interaction ◽  
Basis Set ◽  
Coupled Cluster ◽  
Interaction Energies ◽  
Cluster Approach ◽  
Explicitly Correlated

The X40x10 Halogen Bonding Benchmark Revisited: Surprising Importance of (n-1)d Subvalence Correlation

2018 ◽  
Author(s):  
Manoj Kumar Kesharwani ◽  
Nitai Sylvetsky ◽  
Debashree Manna ◽  
Jan M.L. Martin
Keyword(s):  
Noncovalent Interactions ◽  
Halogen Bonding ◽  
Basis Set ◽  
Basis Sets ◽  
Coupled Cluster ◽  
Dissociation Energies ◽  
Explicitly Correlated ◽  
Two Factors ◽  
High Level ◽  
Cluster Methods

<p>We have re-evaluated the X40x10 benchmark for halogen bonding using conventional and explicitly correlated coupled cluster methods. For the aromatic dimers at small separation, improved CCSD(T)–MP2 “high-level corrections” (HLCs) cause substantial reductions in the dissociation energy. For the bromine and iodine species, (n-1)d subvalence correlation increases dissociation energies, and turns out to be more important for noncovalent interactions than is generally realized; ; (n-1)sp subvalence correlation is much less important. The (n-1)d subvalence term is dominated by core-valence correlation; with the smaller cc-pVDZ-F12-PP and cc-pVTZ-F12-PP basis sets, basis set convergence for the core-core contribution becomes sufficiently erratic that it may compromise results overall. The two factors conspire to generate discrepancies of up to 0.9 kcal/mol (0.16 kcal/mol RMS) between the original X40x10 data and the present revision.</p>

A simple model for halogen bonds

2018 ◽  
Author(s):  
Robert A. Shaw ◽  
Grant Hill
Keyword(s):  
Simple Model ◽  
Statistical Model ◽  
Halogen Bond ◽  
Coupled Cluster ◽  
Interaction Energies ◽  
Halogen Bonds ◽  
Bond Interaction ◽  
Explicitly Correlated ◽  
Equilibrium Geometries

In this article we develop a simple statistical model for the prediction of halogen bond interaction energies at equilibrium geometries. The model is based on explicitly correlated coupled cluster results and produces root-mean-squared deviations of 0.14 and 0.28 kcal mol<sup>–1</sup> over separate fitting and validation sets, respectively. We also show how the model can be used to highlight cases where induction or dispersion significantly affect the underlying nature of the interaction.<br>

The X40x10 Halogen Bonding Benchmark Revisited: Surprising Importance of (n-1)d Subvalence Correlation

2018 ◽  
Author(s):  
Manoj Kumar Kesharwani ◽  
Nitai Sylvetsky ◽  
Debashree Manna ◽  
Jan M.L. Martin
Keyword(s):  
Noncovalent Interactions ◽  
Halogen Bonding ◽  
Basis Set ◽  
Basis Sets ◽  
Coupled Cluster ◽  
Dissociation Energies ◽  
Explicitly Correlated ◽  
Two Factors ◽  
High Level ◽  
Cluster Methods

<p>We have re-evaluated the X40x10 benchmark for halogen bonding using conventional and explicitly correlated coupled cluster methods. For the aromatic dimers at small separation, improved CCSD(T)–MP2 “high-level corrections” (HLCs) cause substantial reductions in the dissociation energy. For the bromine and iodine species, (n-1)d subvalence correlation increases dissociation energies, and turns out to be more important for noncovalent interactions than is generally realized; ; (n-1)sp subvalence correlation is much less important. The (n-1)d subvalence term is dominated by core-valence correlation; with the smaller cc-pVDZ-F12-PP and cc-pVTZ-F12-PP basis sets, basis set convergence for the core-core contribution becomes sufficiently erratic that it may compromise results overall. The two factors conspire to generate discrepancies of up to 0.9 kcal/mol (0.16 kcal/mol RMS) between the original X40x10 data and the present revision.</p>

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