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Martin Headgordon - One of the best experts on this subject based on the ideXlab platform.
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systematically improvable tensor hypercontraction interpolative separable density fitting for molecules applied to exact exchange second and third order moller plesset perturbation theory
Journal of Chemical Theory and Computation, 2020Co-Authors: Joonho Lee, Lin Lin, Martin HeadgordonAbstract:We present a systematically improvable tensor hypercontraction (THC) factorization based on interpolative separable density fitting (ISDF). We illustrate algorithmic details to achieve this within the framework of Becke's atom-centered quadrature grid. A single ISDF parameter cISDF controls the tradeoff between accuracy and cost. In particular, cISDF sets the number of interpolation points used in THC, NIP = cISDF x NX with NX being the number of auxiliary basis functions. In conjunction with the resolution-of-the-identity (RI) technique, we develop and investigate the THC-RI algorithms for cubic-scaling exact exchange for Hartree-Fock and range-separated hybrids (e.g., ωB97X-V) and quartic-scaling second- and third-order M{\o}ller-Plesset theory (MP2 and MP3). These algorithms were evaluated over the W4-11 thermochemistry (Atomization Energy) set and A24 non-covalent interaction benchmark set with commonly used Dunning's basis sets (cc-pVDZ, cc-pVTZ, aug-cc-pVDZ, and aug-cc-pVTZ). We demonstrate the conv...
Jan M L Martin - One of the best experts on this subject based on the ideXlab platform.
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benchmark Atomization Energy of ethane importance of accurate zero point vibrational energies and diagonal born oppenheimer corrections for a simple organic molecule
Journal of Molecular Structure-theochem, 2007Co-Authors: Amir Karton, Branko Ruscic, Jan M L MartinAbstract:Abstract A benchmark calculation of the Atomization Energy of the ‘simple’ organic molecule C 2 H 6 (ethane) has been carried out by means of W4 theory. While the molecule is straightforward in terms of one-particle and n -particle basis set convergence, its large zero-point vibrational Energy (and anharmonic correction thereto) and nontrivial diagonal Born–Oppenheimer correction (DBOC) represent interesting challenges. For the W4 set of molecules and C 2 H 6 , we show that DBOCs to the total Atomization Energy are systematically overestimated at the SCF level, and that the correlation correction converges very rapidly with the basis set. Thus, even at the CISD/cc-pVDZ level, useful correlation corrections to the DBOC are obtained. When applying such a correction, overall agreement with experiment was only marginally improved, but a more significant improvement is seen when hydrogen-containing systems are considered in isolation. We conclude that for closed-shell organic molecules, the greatest obstacles to highly accurate computational thermochemistry may not lie in the solution of the clamped-nuclei Schrodinger equation, but rather in the zero-point vibrational Energy and the diagonal Born–Oppenheimer correction.
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a definitive heat of vaporization of silicon through benchmark ab initio calculations on sif4
Journal of Physical Chemistry A, 1999Co-Authors: Jan M L Martin, Peter R TaylorAbstract:To resolve a significant uncertainty in the heat of vaporization of silicona fundamental parameter in gas-phase thermochemistryΔH°f,0 [Si(g)] has been determined from a thermochemical cycle involving the precisely known experimental heats of formation of SiF4(g) and F(g) and a benchmark calculation of the total Atomization Energy (TAE0) of SiF4 using coupled-cluster methods. Basis sets up to [8s7p6d4f2g1h] on Si and [7s6p5d4f3g2h] on F have been employed, and extrapolations for residual basis set incompleteness applied. The contributions of inner-shell correlation (−0.08 kcal/mol), scalar relativistic effects (−1.88 kcal/mol), atomic spin−orbit splitting (−1.97 kcal/mol), and anharmonicity in the zero-point Energy (+0.04 kcal/mol) have all been explicitly accounted for. Our benchmark TAE0 = 565.89 ± 0.22 kcal/mol leads to ΔH°f,0 [Si(g)] = 107.15 ± 0.38 kcal/mol (ΔH°f,298 [Si(g)] = 108.19 ± 0.38 kcal/mol): between the JANAF/CODATA value of 106.5 ± 1.9 kcal/mol and the revised value proposed by Grev and Sc...
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a definitive heat of vaporization of silicon through benchmark ab initio calculations on sif_4
arXiv: Chemical Physics, 1999Co-Authors: Jan M L Martin, Peter R TaylorAbstract:In order to resolve a significant uncertainty in the heat of vaporization of silicon -- a fundamental parameter in gas-phase thermochemistry -- $\Delta H^\circ_{f,0}$[Si(g)] has been determined from a thermochemical cycle involving the precisely known experimental heats of formation of SiF_4(g) and F(g) and a benchmark calculation of the total Atomization Energy (TAE_0) of SiF_4 using coupled-cluster methods. Basis sets up to $[8s7p6d4f2g1h]$ on Si and $[7s6p5d4f3g2h]$ on F have been employed, and extrapolations for residual basis set incompleteness applied. The contributions of inner-shell correlation (-0.08 kcal/mol), scalar relativistic effects (-1.88 kcal/mol), atomic spin-orbit splitting (-1.97 kcal/mol), and anharmonicity in the zero-point Energy (+0.04 kcal/mol) have all been explicitly accounted for. Our benchmark TAE_0=565.89 \pm 0.22 kcal/mol leads to $\Delta H^\circ_{f,0}$[Si(g)]=107.15 \pm 0.38 kcal/mol ($\Delta H^\circ_{f,298}$[Si(g)]=108.19 \pm 0.38 kcal/mol): between the JANAF/CODATA value of 106.5 \pm 1.9 kcal/mol and the revised value proposed by Grev and Schaefer [J. Chem. Phys. 97, 8389 (1992}], 108.1 \pm 0.5 kcal/mol. The revision will be relevant for future computational studies on heats of formation of silicon compounds.
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basis set convergence study of the Atomization Energy geometry and anharmonic force field of so2 the importance of inner polarization functions
Journal of Chemical Physics, 1998Co-Authors: Jan M L MartinAbstract:The total Atomization energies, geometries, and anharmonic force fields of the SO and SO2 molecules have been studied at the augmented coupled cluster [CCSD(T)] level near the one-particle basis set limit. The effect of core correlation has been accounted for. The addition of high-exponent d and f “inner polarization functions” to the sulfur basis set was found to be essential for obtaining reliable molecular geometries. The differential effect of core correlation on computed properties is in fact much less important. The CCSD(T) one-particle basis set limit for the symmetric stretching frequencies appears to be higher than the exact value, while the antisymmetric stretching frequency benefits from an error cancellation. The basis set extension effects of diffuse functions and inner polarization functions appear to be nearly perfectly additive. Our best computed Atomization energies and geometries agree to within 0.1 kcal/mol, 0.0004 A, and 0.03 degrees with experiment: The errors in the fundamentals of S...
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the Atomization Energy and proton affinity of nh3 an ab initio calibration study
Chemical Physics Letters, 1996Co-Authors: Jan M L Martin, Timothy J. LeeAbstract:Abstract The total Atomization Energy and proton affinity of NH 3 have been subjected to an extensive convergence study involving basis sets of up to spdfgh quality. Our best extrapolated Σ D 0 = 276.5 kcal/mol lies only 0.2 kcal/mol below the experimental value. Our recommended value for PA 298 , 203.9±0.3 kcal/mol, is in excellent agreement with the most recent experimental value but has a smaller error margin. It is found that augmented basis sets are desirable when determining proton affinities using the empirical correction for further basis set expansion proposed in J. Chem. Phys. 97 (1992) 5012.
Joonho Lee - One of the best experts on this subject based on the ideXlab platform.
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systematically improvable tensor hypercontraction interpolative separable density fitting for molecules applied to exact exchange second and third order moller plesset perturbation theory
Journal of Chemical Theory and Computation, 2020Co-Authors: Joonho Lee, Lin Lin, Martin HeadgordonAbstract:We present a systematically improvable tensor hypercontraction (THC) factorization based on interpolative separable density fitting (ISDF). We illustrate algorithmic details to achieve this within the framework of Becke's atom-centered quadrature grid. A single ISDF parameter cISDF controls the tradeoff between accuracy and cost. In particular, cISDF sets the number of interpolation points used in THC, NIP = cISDF x NX with NX being the number of auxiliary basis functions. In conjunction with the resolution-of-the-identity (RI) technique, we develop and investigate the THC-RI algorithms for cubic-scaling exact exchange for Hartree-Fock and range-separated hybrids (e.g., ωB97X-V) and quartic-scaling second- and third-order M{\o}ller-Plesset theory (MP2 and MP3). These algorithms were evaluated over the W4-11 thermochemistry (Atomization Energy) set and A24 non-covalent interaction benchmark set with commonly used Dunning's basis sets (cc-pVDZ, cc-pVTZ, aug-cc-pVDZ, and aug-cc-pVTZ). We demonstrate the conv...
Lin Lin - One of the best experts on this subject based on the ideXlab platform.
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systematically improvable tensor hypercontraction interpolative separable density fitting for molecules applied to exact exchange second and third order moller plesset perturbation theory
Journal of Chemical Theory and Computation, 2020Co-Authors: Joonho Lee, Lin Lin, Martin HeadgordonAbstract:We present a systematically improvable tensor hypercontraction (THC) factorization based on interpolative separable density fitting (ISDF). We illustrate algorithmic details to achieve this within the framework of Becke's atom-centered quadrature grid. A single ISDF parameter cISDF controls the tradeoff between accuracy and cost. In particular, cISDF sets the number of interpolation points used in THC, NIP = cISDF x NX with NX being the number of auxiliary basis functions. In conjunction with the resolution-of-the-identity (RI) technique, we develop and investigate the THC-RI algorithms for cubic-scaling exact exchange for Hartree-Fock and range-separated hybrids (e.g., ωB97X-V) and quartic-scaling second- and third-order M{\o}ller-Plesset theory (MP2 and MP3). These algorithms were evaluated over the W4-11 thermochemistry (Atomization Energy) set and A24 non-covalent interaction benchmark set with commonly used Dunning's basis sets (cc-pVDZ, cc-pVTZ, aug-cc-pVDZ, and aug-cc-pVTZ). We demonstrate the conv...
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Systematically Improvable Tensor Hypercontraction: Interpolative Separable Density-Fitting for Molecules Applied to Exact Exchange, Second- and Third-Order Møller-Plesset Perturbation Theory.
eScholarship University of California, 2020Co-Authors: Lee Joonho, Lin Lin, Head-gordon MartinAbstract:We present a systematically improvable tensor hypercontraction (THC) factorization based on interpolative separable density fitting (ISDF). We illustrate algorithmic details to achieve this within the framework of Becke's atom-centered quadrature grid. A single ISDF parameter cISDF controls the trade-off between accuracy and cost. In particular, cISDF sets the number of interpolation points used in THC, NIP = cISDF × NX with NX being the number of auxiliary basis functions. In conjunction with the resolution-of-the-identity (RI) technique, we develop and investigate the THC-RI algorithms for cubic-scaling exact exchange for Hartree-Fock and range-separated hybrids (e.g., ωB97X-V) and quartic-scaling second- and third-order Møller-Plesset theory (MP2 and MP3). These algorithms were evaluated over the W4-11 thermochemistry (Atomization Energy) set and A24 noncovalent interaction benchmark set with standard Dunning basis sets (cc-pVDZ, cc-pVTZ, aug-cc-pVDZ, and aug-cc-pVTZ). We demonstrate the convergence of THC-RI algorithms to numerically exact RI results using ISDF points. Based on these, we make recommendations on cISDF for each basis set and method. We also demonstrate the utility of THC-RI exact exchange and MP2 for larger systems such as water clusters and C20. We stress that more challenges await in obtaining accurate and numerically stable THC factorization for wave function amplitudes as well as for the space spanned by virtual orbitals in large basis sets and implementing sparsity-aware THC-RI algorithms
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Systematically Improvable Tensor Hypercontraction: Interpolative Separable Density-Fitting for Molecules Applied to Exact Exchange, Second- and Third-Order M{\o}ller-Plesset Perturbation Theory
'American Chemical Society (ACS)', 2019Co-Authors: Lee Joonho, Lin Lin, Head-gordon MartinAbstract:We present a systematically improvable tensor hypercontraction (THC) factorization based on interpolative separable density fitting (ISDF). We illustrate algorithmic details to achieve this within the framework of Becke's atom-centered quadrature grid. A single ISDF parameter $c_\text{ISDF}$ controls the tradeoff between accuracy and cost. In particular, $c_\text{ISDF}$ sets the number of interpolation points used in THC, $N_\text{IP} = c_\text{ISDF}\times N_\text{X}$ with $N_\text{X}$ being the number of auxiliary basis functions. In conjunction with the resolution-of-the-identity (RI) technique, we develop and investigate the THC-RI algorithms for cubic-scaling exact exchange for Hartree-Fock and range-separated hybrids (e.g., $\omega$B97X-V) and quartic-scaling second- and third-order M{\o}ller-Plesset theory (MP2 and MP3). These algorithms were evaluated over the W4-11 thermochemistry (Atomization Energy) set and A24 non-covalent interaction benchmark set with standard Dunning basis sets (cc-pVDZ, cc-pVTZ, aug-cc-pVDZ, and aug-cc-pVTZ). We demonstrate the convergence of THC-RI algorithms to numerically exact RI results using ISDF points. Based on these, we make recommendations on $c_\text{ISDF}$ for each basis set and method. We also demonstrate the utility of THC-RI exact exchange and MP2 for larger systems such as water clusters and $\text{C}_{20}$. We stress that more challenges await in obtaining accurate and numerically stable THC factorization for wavefunction amplitudes as well as the space spanned by virtual orbitals in large basis sets and implementing sparsity-aware THC-RI algorithms
Nathan E Schultz - One of the best experts on this subject based on the ideXlab platform.
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design of density functionals by combining the method of constraint satisfaction with parametrization for thermochemistry thermochemical kinetics and noncovalent interactions
Journal of Chemical Theory and Computation, 2006Co-Authors: Yan Zhao, Nathan E Schultz, Donald G TruhlarAbstract:We present a new hybrid meta exchange-correlation functional, called M05-2X, for thermochemistry, thermochemical kinetics, and noncovalent interactions. We also provide a full discussion of the new M05 functional, previously presented in a short communication. The M05 functional was parametrized including both metals and nonmetals, whereas M05-2X is a high-nonlocality functional with double the amount of nonlocal exchange (2X) that is parametrized only for nonmetals. In particular, M05 was parametrized against 35 data values, and M05-2X is parametrized against 34 data values. Both functionals, along with 28 other functionals, have been comparatively assessed against 234 data values: the MGAE109/3 main-group Atomization Energy database, the IP13/3 ionization potential database, the EA13/3 electron affinity database, the HTBH38/4 database of barrier height for hydrogen-transfer reactions, five noncovalent databases, two databases involving metal−metal and metal−ligand bond energies, a dipole moment databas...
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databases for transition element bonding metal metal bond energies and bond lengths and their use to test hybrid hybrid meta and meta density functionals and generalized gradient approximations
Journal of Physical Chemistry A, 2005Co-Authors: Nathan E SchultzAbstract:We propose a data set of bond lengths for 8 selected transition metal dimers (Ag2, Cr2, Cu2, CuAg, Mo2, Ni2, V2, and Zr2) and another data set containing their Atomization energies and the Atomization Energy of ZrV, and we use these for testing density functional theory. The molecules chosen for the test sets were selected on the basis of the expected reliability of the data and their ability to constitute a diverse and representative set of transition element bond types while the data sets are kept small enough to allow for efficient testing of a large number of computational methods against a very reliable subset of experimental data. In this paper we test 42 different functionals: 2 local spin density approximation (LSDA) functionals, 12 generalized gradient approximation (GGA) methods, 13 hybrid GGAs, 7 meta GGA methods, and 8 hybrid meta GGAs. We find that GGA density functionals are more accurate for the Atomization energies of pure transition metal systems than are their meta, hybrid, or hybrid me...
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databases for transition element bonding metal metal bond energies and bond lengths and their use to test hybrid hybrid meta and meta density functionals and generalized gradient approximations
Journal of Physical Chemistry A, 2005Co-Authors: Nathan E SchultzAbstract:We propose a data set of bond lengths for 8 selected transition metal dimers (Ag(2), Cr(2), Cu(2), CuAg, Mo(2), Ni(2), V(2), and Zr(2)) and another data set containing their Atomization energies and the Atomization Energy of ZrV, and we use these for testing density functional theory. The molecules chosen for the test sets were selected on the basis of the expected reliability of the data and their ability to constitute a diverse and representative set of transition element bond types while the data sets are kept small enough to allow for efficient testing of a large number of computational methods against a very reliable subset of experimental data. In this paper we test 42 different functionals: 2 local spin density approximation (LSDA) functionals, 12 generalized gradient approximation (GGA) methods, 13 hybrid GGAs, 7 meta GGA methods, and 8 hybrid meta GGAs. We find that GGA density functionals are more accurate for the Atomization energies of pure transition metal systems than are their meta, hybrid, or hybrid meta analogues. We find that the errors for Atomization energies and bond lengths are not as large if we limit ourselves to dimers with small amounts of multireference character. We also demonstrate the effects of increasing the fraction of Hartree-Fock exchange in multireference systems by computing the potential Energy curve for Cr(2) and Mo(2) with several functionals. We also find that BLYP is the most accurate functional for bond energies and is reasonably accurate for bond lengths. The methods that work well for transition metal bonds are found to be quite different from those that work well for organic and other main group chemistry.