Journal ArticleDOI
Enthalpy difference between conformations of normal alkanes: Intramolecular basis set superposition error (BSSE) in the case of n-butane and n-hexane
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In this paper, an extra error source for high-quality ab initio calculation of conformation equilibrium in normal alkanes-intramolecular basis set superposition error (BSSE)-is discussed.Abstract:
In this paper, an extra error source for high-quality ab initio calculation of conformation equilibrium in normal alkanes—intramolecular basis set superposition error (BSSE)—is discussed. Normal butane (n-butane) and normal hexane (n-hexane) are used as representative examples. Single-point energy difference and BSSE values of trans and gauche conformations for n-butane (and trans-trans-trans and gauche-gauche-gauche conformations for n-hexane) were calculated using popular electron correlation methods: The second-order Moller–Plesset (MP2), the fourth-order Moller–Plesset (MP4), and coupled cluster with single and double substitutions with noniterative triple excitation [CCSD(T)] levels of theory. Extrapolation to the complete basis set is applied. The difference between BSSE-corrected and uncorrected relative energy values ranges from ∼100 cal/mol (in case of n-butane) to more than 1000 cal/mol (in case of n-hexane). The influence of basis set type (Pople or Dunning) and size [up to 6-311G(3df,3pd) and ...read more
Citations
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Journal ArticleDOI
A geometrical correction for the inter- and intra-molecular basis set superposition error in Hartree-Fock and density functional theory calculations for large systems.
Holger Kruse,Stefan Grimme +1 more
TL;DR: A semi-empirical counterpoise-type correction for basis set superposition error (BSSE) in molecular systems is presented, and an atom pair-wise potential corrects for the inter- and intra- molecular BSSE in supermolecular Hartree-Fock (HF) or density functional theory (DFT) calculations.
Journal ArticleDOI
Why the Standard B3LYP/6-31G* Model Chemistry Should Not Be Used in DFT Calculations of Molecular Thermochemistry: Understanding and Correcting the Problem
TL;DR: The B3LYP-gCP-D3/6-31G* scheme is presented, which corrects for missing London dispersion and basis set superposition error (BSSE) in a physically sound manner and is meant to fully substitute standard B3lyP/ 6-31 G* calculations in the same black-box sense at essentially no increase in computational cost.
Journal ArticleDOI
Good Computational Practice in the Assignment of Absolute Configurations by TDDFT Calculations of ECD Spectra.
Gennaro Pescitelli,Torsten Bruhn +1 more
TL;DR: A discussion on what can be called good computational practice in running TDDFT ECD calculations, highlighting the most crucial points with several examples from the recent literature is presented.
Journal ArticleDOI
Gasoline classification using near infrared (NIR) spectroscopy data: Comparison of multivariate techniques
TL;DR: NIR spectroscopy was found to be effective for gasoline classification purposes, when compared with nuclear magnetic resonance (NMR)Spectroscopy or gas chromatography (GC), and KNN, SVM, and PNN techniques for classification were find to be among the most effective ones.
Journal ArticleDOI
Neural network (ANN) approach to biodiesel analysis: Analysis of biodiesel density, kinematic viscosity, methanol and water contents using near infrared (NIR) spectroscopy
TL;DR: In this article, the authors compared the performance of linear and non-linear calibration techniques, namely, multiple linear regression (MLR), principal component regression (PCR), partial least squares regression (PLS), polynomial and Spline-PLS versions, and artificial neural networks (ANN) for prediction of biodiesel properties from near infrared spectra.
References
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Journal ArticleDOI
Note on an Approximation Treatment for Many-Electron Systems
Chr. Møller,Milton S. Plesset +1 more
TL;DR: In this article, a perturbation theory for treating a system of n electrons in which the Hartree-Fock solution appears as the zero-order approximation was developed, and it was shown by this development that the first order correction for the energy and the charge density of the system is zero.
Journal ArticleDOI
Quadratic configuration interaction. A general technique for determining electron correlation energies
TL;DR: In this article, a general procedure for calculation of the electron correlation energy, starting from a single Hartree-Fock determinant, is introduced, and the relation of this method to coupled-cluster (CCSD) theory is discussed.
Journal ArticleDOI
MP2 energy evaluation by direct methods
TL;DR: In this paper, an efficient algorithm for evaluating the second-order Moller-Plesset (MP2) energy directly from two-electron integrals in the atomic orbital basis, i.e., the integrals are not stored.
Journal ArticleDOI
Basis-set convergence of correlated calculations on water
TL;DR: In this paper, the basis-set convergence of the electronic correlation energy in the water molecule is investigated at the second-order Mo/ller-Plesset level and at the coupled-cluster singles-and-doubles level with and without perturbative triples corrections applied.
Book ChapterDOI
Chapter 41 – Advances in electronic structure theory: GAMESS a decade later
TL;DR: GAMESS as discussed by the authors is a suite of electronic structure and QM/MM methods (including open-and closed-shell Hartree-Fock which has been essentially ignored here) that can be run on virtually any computer, cluster, massively parallel system or for that matter a desktop Mac or PC.