THEORETICAL STUDIES ON HEATS OF FORMATION FOR SOME THIOL COMPOUNDS BY DENSITY FUNCTIONAL THEORY AND CBS-Q METHOD

Quantum chemical calculations are used to estimate the bond dissociation energies (BDEs) for 15 thiol compounds. These compounds are studied by employing the hybrid density functional theory (B3LYP, B3PW91, B3P86, PBE0) methods and the complete basis set (CBS-Q) method together with 6-311G** basis set. It is demonstrated that B3P86 and CBS-Q methods are accurate for computing the reliable BDEs for thiol compounds. In order to test whether the non-local BLYP method suggested by Fu et al.19 is general for our study and whether B3P86 method has a low basis set sensitivity, the BDEs for seven thiol compounds are also calculated using BLYP/6-31+G* and B3P86 method with 6-31+G*, 6-31+G**, and 6-311+G** basis sets for comparison. The obtained results are compared with the available experimental results. It is noted that B3P86 method is not sensitive to the basis set. Considering the inevitable computational cost of CBS-Q method and the reliability of the B3P86 calculations, B3P86 method with a moderate or a larger basis set may be more suitable to calculate the BDEs of the C–SH bond for thiol compounds.

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Basis Set Extrapolations for Density Functional Theory

10.26434/chemrxiv.12552998.v1 ◽

2020 ◽

Author(s):

Peter Kraus

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Computational Cost ◽

Basis Set ◽

Basis Sets ◽

Density Functionals ◽

Functional Theory ◽

Common Basis ◽

Basis Set Extrapolation

Improving results of correlated wavefunction theory calculations by extrapolating from successive basis sets is nowadays a common practice. However, such approaches are uncommon in density functional theory, especially due its faster convergence towards the basis set limit. In this work I present approaches for basis set extrapolation in density functional theory that enable users to obtain results of 4-zeta quality from 3- and 2-zeta calculations, i.e. at a fraction of the computational cost. The extrapolation techniques work well with modern density functionals and common basis sets.

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Basis Set Extrapolations for Density Functional Theory

10.26434/chemrxiv.12552998 ◽

2020 ◽

Author(s):

Peter Kraus

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Computational Cost ◽

Basis Set ◽

Basis Sets ◽

Density Functionals ◽

Functional Theory ◽

Common Basis ◽

Basis Set Extrapolation

Improving results of correlated wavefunction theory calculations by extrapolating from successive basis sets is nowadays a common practice. However, such approaches are uncommon in density functional theory, especially due its faster convergence towards the basis set limit. In this work I present approaches for basis set extrapolation in density functional theory that enable users to obtain results of 4-zeta quality from 3- and 2-zeta calculations, i.e. at a fraction of the computational cost. The extrapolation techniques work well with modern density functionals and common basis sets.

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THEORETICAL STUDIES ON BOND DISSOCIATION ENERGIES FOR SOME ALIPHATIC ALCOHOL COMPOUNDS BY DENSITY FUNCTIONAL THEORY AND CBS-Q METHOD

Journal of Theoretical and Computational Chemistry ◽

10.1142/s0219633611006335 ◽

2011 ◽

Vol 10 (02) ◽

pp. 179-189 ◽

Cited By ~ 4

Author(s):

XIAO-HONG LI ◽

GENG-XIN YIN ◽

XIAN-ZHOU ZHANG

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Aliphatic Alcohol ◽

Basis Set ◽

Basis Sets ◽

Q Method ◽

Bond Dissociation Energies ◽

Functional Theory ◽

Bond Dissociation ◽

Dissociation Energies

Quantum chemical calculations are used to estimate the bond dissociation energies (BDEs) for 20 aliphatic alcohol compounds. These compounds are studied by employing the hybrid density functional theory (B3LYP, B3PW91, and B3P86) methods with 6-311G** basis set and the complete basis set (CBS-Q) method together. It is demonstrated that B3P86 and CBS-Q methods are accurate to compute the reliable BDEs for aliphatic alcohol compounds. In order to test whether the non-local BLYP method suggested by Jursic18 is general for our study and whether B3P86 method has a low basis set sensitivity, the BDEs for 20 aliphatic alcohol compounds are also calculated using BLYP/6-31+G*, BLYP/6-31G*, and B3P86 methods with 6-31G*, 6-31+G*, and 6-31G** basis sets for comparison. The obtained results are compared with the available experimental results. It is noted that B3P86 method is sensitive to the basis sets. Considering the inevitably computational cost of CBS-Q method and the reliability of the B3P86 calculation, B3P86 method with 6-31G** basis set may be more suitable to calculate the BDEs of the C–O bond for aliphatic alcohol compounds.

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Benchmark of Simplified Time-Dependent Density Functional Theory for UV-Vis Spectral Properties of Porphyrinoids

10.26434/chemrxiv.9912860 ◽

2019 ◽

Author(s):

Kamal Batra ◽

Stefan Zahn ◽

Thomas Heine

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Large Scale ◽

Absolute Error ◽

Time Dependent ◽

Basis Set ◽

Basis Sets ◽

Functional Theory ◽

Framework Materials ◽

Dependent Density

We thoroughly benchmark time-dependent density- functional theory for the predictive calculation of UV/Vis spectra of porphyrin derivatives. With the aim to provide an approach that is computationally feasible for large-scale applications such as biological systems or molecular framework materials, albeit performing with high accuracy for the Q-bands, we compare the results given by various computational protocols, including basis sets, density-functionals (including gradient corrected local functionals, hybrids, double hybrids and range-separated functionals), and various variants of time-dependent density-functional theory, including the simplified Tamm-Dancoff approximation. An excellent choice for these calculations is the range-separated functional CAM-B3LYP in combination with the simplified Tamm-Dancoff approximation and a basis set of double-ζ quality def2-SVP (mean absolute error [MAE] of ~0.05 eV). This is not surpassed by more expensive approaches, not even by double hybrid functionals, and solely systematic excitation energy scaling slightly improves the results (MAE ~0.04 eV).

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Accurate quadruple-ζ basis-set approximation for double-hybrid density functional theory with an order of magnitude reduction in computational cost

Theoretical Chemistry Accounts ◽

10.1007/s00214-013-1426-9 ◽

2013 ◽

Vol 133 (2) ◽

Cited By ~ 18

Author(s):

Bun Chan ◽

Leo Radom

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Computational Cost ◽

Basis Set ◽

Hybrid Density Functional Theory ◽

Functional Theory ◽

Order Of Magnitude ◽

Set Approximation ◽

Hybrid Density Functional

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Fast computation of DFT nuclear gradient with multiresolution*This article is dedicated to Dr. Russell J. Boyd for his distinguished career in chemical research.

Canadian Journal of Chemistry ◽

10.1139/v11-063 ◽

2011 ◽

Vol 89 (6) ◽

pp. 657-662 ◽

Cited By ~ 2

Author(s):

Nicholas J. Russ ◽

Chun-min Chang ◽

Jing Kong

Keyword(s):

Density Functional Theory ◽

Electron Density ◽

Density Functional ◽

Density Functional Theory Calculation ◽

Computational Cost ◽

Basis Sets ◽

Local Spin Density Approximation ◽

Functional Theory ◽

Exchange Correlation ◽

The Impact

We present an efficient algorithm for evaluating the exchange-correlation contribution to the nuclear gradients of density-functional theory calculation within the local spin-density approximation. The algorithm is an extension of the multiresolution exchange-correlation (mrXC) method, which treats smooth and compact parts of the electron density separately. The nuclear gradient of the smooth density is calculated on the even-spaced grid while the compact part of the density is handled on the normal atom-centered grid (ACG). The overall formulism is still formally based on the ACG, and thus does not change the results of the existing ACG-based algorithms for all-electron density-functional theory (DFT) calculations. The variation of the positions and weights of ACG owing to the nuclear perturbation is also handled rigorously. Benchmark calculations with different basis sets and sizes of ACG show that mrXC reduces the computational cost by several times without loss of accuracy. It also lessens the impact on the CPU time when the size of the ACG is increased.

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Benchmark of Simplified Time-Dependent Density Functional Theory for UV-Vis Spectral Properties of Porphyrinoids

10.26434/chemrxiv.9912860.v2 ◽

2019 ◽

Author(s):

Kamal Batra ◽

Stefan Zahn ◽

Thomas Heine

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Large Scale ◽

Absolute Error ◽

Time Dependent ◽

Basis Set ◽

Basis Sets ◽

Functional Theory ◽

Framework Materials ◽

Dependent Density

We thoroughly benchmark time-dependent density- functional theory for the predictive calculation of UV/Vis spectra of porphyrin derivatives. With the aim to provide an approach that is computationally feasible for large-scale applications such as biological systems or molecular framework materials, albeit performing with high accuracy for the Q-bands, we compare the results given by various computational protocols, including basis sets, density-functionals (including gradient corrected local functionals, hybrids, double hybrids and range-separated functionals), and various variants of time-dependent density-functional theory, including the simplified Tamm-Dancoff approximation. An excellent choice for these calculations is the range-separated functional CAM-B3LYP in combination with the simplified Tamm-Dancoff approximation and a basis set of double-ζ quality def2-SVP (mean absolute error [MAE] of ~0.05 eV). This is not surpassed by more expensive approaches, not even by double hybrid functionals, and solely systematic excitation energy scaling slightly improves the results (MAE ~0.04 eV).

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Approaching the Basis Set Limit in Density Functional Theory Calculations Using Dual Basis Sets without Diagonalization†

The Journal of Physical Chemistry A ◽

10.1021/jp0374713 ◽

2004 ◽

Vol 108 (15) ◽

pp. 3206-3210 ◽

Cited By ~ 61

Author(s):

Liang ◽

Martin Head-Gordon

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Density Functional Theory Calculations ◽

Basis Set ◽

Basis Sets ◽

Dual Basis ◽

Functional Theory

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A density functional theory study of the free radicals NH2, NF2, NCl2, PH2, PF2, and PCl2

Canadian Journal of Chemistry ◽

10.1139/v94-094 ◽

1994 ◽

Vol 72 (3) ◽

pp. 695-704 ◽

Cited By ~ 18

Author(s):

Maggie A. Austen ◽

Leif A. Eriksson ◽

Russell J. Boyd

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Local Density ◽

Basis Set ◽

Basis Sets ◽

Functional Theory ◽

Unpaired Spin ◽

Non Local ◽

Local Potentials ◽

Spin Densities

The linear combination of Gaussian-type orbitals–density functional theory (LCGTO–DFT) approach is used to study geometries and hyperfine structures of a set of neutral radicals. Each of the title molecules is investigated by means of local density approximation calculations, and using the Becke–Perdew and Perdew–Wang–Perdew corrections to the exchange and correlation functionals. The effects of local vs. non-local potentials and of various basis sets are investigated. Total densities and unpaired spin densities are compared. The isotropic couplings are found to be very dependent on the type of exchange functional used, whereas the anisotropic couplings are relatively insensitive to the choice of basis set and functional. In most cases, the Perdew–Wang exchange corrections provide isotropic couplings in satisfactory agreement with experiment.

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