Small Atomic Orbital Basis Set First‐Principles Quantum Chemical Methods for Large Molecular and Periodic Systems: A Critical Analysis of Error Sources

Abstract

In quantum chemical computations the combination of Hartree–Fock or a density functional theory (DFT) approximation with relatively small atomic orbital basis sets of double‐zeta quality is still widely used, for example, in the popular B3LYP/6‐31G* approach. In this Review, we critically analyze the two main sources of error in such computations, that is, the basis set superposition error on the one hand and the missing London dispersion interactions on the other. We review various strategies to correct those errors and present exemplary calculations on mainly noncovalently bound systems of widely varying size. Energies and geometries of small dimers, large supramolecular complexes, and molecular crystals are covered. We conclude that it is not justified to rely on fortunate error compensation, as the main inconsistencies can be cured by modern correction schemes which clearly outperform the plain mean‐field methods.

Good Computational Practice in the Assignment of Absolute Configurations by TDDFT Calculations of ECD Spectra

“…10 As for the basis set, a double-ζ Pople's type basis set such as 6-31G(d) may be unsuited to calculate geometries and relative energies accurately enough, especially due to the intramolecular basis set superposition error (BSSE). [46][47][48] A larger basis set should be considered at least in single-point or frequency calculations to estimate internal or free energies (step 2b in our flowchart). Time-saving approaches such as the resolution of identity method 49 or the chain-of-spheres approximation 50 may be useful in combination with large basis sets.…”

Modeling from Theory and Modeling from Data: Complementary or Alternative Approaches? The Case of Ionic Liquids

“…CODESSA derives descriptors by using quantum mechanical methods to develop QSAR (quantitative structure–activity relationship/QSPR models. A critical analysis of error sources in quantum‐chemical computations has been recently reported . The CODESSA approach was adopted to establish QSPR correlations for conductivities and viscosities of low‐temperature‐melting ILs with the bis(trifluoromethylsulfonyl)imide anion.…”

Rotational Barriers of Substituted BIPHEP Ligands: A Comparative Experimental and Theoretical Study

“…DFT methods, however, are a preferred means to calculate rotational barriers . We were aware that some DFT methods are not suited for accurate calculations of weak nonbonding interactions . Recently, one of our authors investigated axially chiral naphthylpyridines and compared the experimentally determined rotational barriers [DHPLC, dynamic NMR (DNMR)] with results obtained by DFT calculations .…”