The Experts below are selected from a list of 497031 Experts worldwide ranked by ideXlab platform
Donald G Truhlar - One of the best experts on this subject based on the ideXlab platform.
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computational thermochemistry Scale Factor databases and Scale Factors for vibrational frequencies obtained from electronic model chemistries
Journal of Chemical Theory and Computation, 2010Co-Authors: I M Alecu, Jingjing Zheng, Yan Zhao, Donald G TruhlarAbstract:Optimized Scale Factors for calculating vibrational harmonic and fundamental frequencies and zero-point energies have been determined for 145 electronic model chemistries, including 119 based on approximate functionals depending on occupied orbitals, 19 based on single-level wave function theory, three based on the neglect-of-diatomic-differential-overlap, two based on doubly hybrid density functional theory, and two based on multicoefficient correlation methods. Forty of the Scale Factors are obtained from large databases, which are also used to derive two universal Scale Factor ratios that can be used to interconvert between Scale Factors optimized for various properties, enabling the derivation of three key Scale Factors at the effort of optimizing only one of them. A reduced Scale Factor optimization model is formulated in order to further reduce the cost of optimizing Scale Factors, and the reduced model is illustrated by using it to obtain 105 additional Scale Factors. Using root-mean-square errors ...
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computational thermochemistry Scale Factor databases and Scale Factors for vibrational frequencies obtained from electronic model chemistries
Journal of Chemical Theory and Computation, 2010Co-Authors: I M Alecu, Jingjing Zheng, Yan Zhao, Donald G TruhlarAbstract:Optimized Scale Factors for calculating vibrational harmonic and fundamental frequencies and zero-point energies have been determined for 145 electronic model chemistries, including 119 based on approximate functionals depending on occupied orbitals, 19 based on single-level wave function theory, three based on the neglect-of-diatomic-differential-overlap, two based on doubly hybrid density functional theory, and two based on multicoefficient correlation methods. Forty of the Scale Factors are obtained from large databases, which are also used to derive two universal Scale Factor ratios that can be used to interconvert between Scale Factors optimized for various properties, enabling the derivation of three key Scale Factors at the effort of optimizing only one of them. A reduced Scale Factor optimization model is formulated in order to further reduce the cost of optimizing Scale Factors, and the reduced model is illustrated by using it to obtain 105 additional Scale Factors. Using root-mean-square errors from the values in the large databases, we find that scaling reduces errors in zero-point energies by a Factor of 2.3 and errors in fundamental vibrational frequencies by a Factor of 3.0, but it reduces errors in harmonic vibrational frequencies by only a Factor of 1.3. It is shown that, upon scaling, the balanced multicoefficient correlation method based on coupled cluster theory with single and double excitations (BMC-CCSD) can lead to very accurate predictions of vibrational frequencies. With a polarized, minimally augmented basis set, the density functionals with zero-point energy Scale Factors closest to unity are MPWLYP1M (1.009), τHCTHhyb (0.989), BB95 (1.012), BLYP (1.013), BP86 (1.014), B3LYP (0.986), MPW3LYP (0.986), and VSXC (0.986).
I M Alecu - One of the best experts on this subject based on the ideXlab platform.
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computational thermochemistry Scale Factor databases and Scale Factors for vibrational frequencies obtained from electronic model chemistries
Journal of Chemical Theory and Computation, 2010Co-Authors: I M Alecu, Jingjing Zheng, Yan Zhao, Donald G TruhlarAbstract:Optimized Scale Factors for calculating vibrational harmonic and fundamental frequencies and zero-point energies have been determined for 145 electronic model chemistries, including 119 based on approximate functionals depending on occupied orbitals, 19 based on single-level wave function theory, three based on the neglect-of-diatomic-differential-overlap, two based on doubly hybrid density functional theory, and two based on multicoefficient correlation methods. Forty of the Scale Factors are obtained from large databases, which are also used to derive two universal Scale Factor ratios that can be used to interconvert between Scale Factors optimized for various properties, enabling the derivation of three key Scale Factors at the effort of optimizing only one of them. A reduced Scale Factor optimization model is formulated in order to further reduce the cost of optimizing Scale Factors, and the reduced model is illustrated by using it to obtain 105 additional Scale Factors. Using root-mean-square errors ...
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computational thermochemistry Scale Factor databases and Scale Factors for vibrational frequencies obtained from electronic model chemistries
Journal of Chemical Theory and Computation, 2010Co-Authors: I M Alecu, Jingjing Zheng, Yan Zhao, Donald G TruhlarAbstract:Optimized Scale Factors for calculating vibrational harmonic and fundamental frequencies and zero-point energies have been determined for 145 electronic model chemistries, including 119 based on approximate functionals depending on occupied orbitals, 19 based on single-level wave function theory, three based on the neglect-of-diatomic-differential-overlap, two based on doubly hybrid density functional theory, and two based on multicoefficient correlation methods. Forty of the Scale Factors are obtained from large databases, which are also used to derive two universal Scale Factor ratios that can be used to interconvert between Scale Factors optimized for various properties, enabling the derivation of three key Scale Factors at the effort of optimizing only one of them. A reduced Scale Factor optimization model is formulated in order to further reduce the cost of optimizing Scale Factors, and the reduced model is illustrated by using it to obtain 105 additional Scale Factors. Using root-mean-square errors from the values in the large databases, we find that scaling reduces errors in zero-point energies by a Factor of 2.3 and errors in fundamental vibrational frequencies by a Factor of 3.0, but it reduces errors in harmonic vibrational frequencies by only a Factor of 1.3. It is shown that, upon scaling, the balanced multicoefficient correlation method based on coupled cluster theory with single and double excitations (BMC-CCSD) can lead to very accurate predictions of vibrational frequencies. With a polarized, minimally augmented basis set, the density functionals with zero-point energy Scale Factors closest to unity are MPWLYP1M (1.009), τHCTHhyb (0.989), BB95 (1.012), BLYP (1.013), BP86 (1.014), B3LYP (0.986), MPW3LYP (0.986), and VSXC (0.986).
Yan Zhao - One of the best experts on this subject based on the ideXlab platform.
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computational thermochemistry Scale Factor databases and Scale Factors for vibrational frequencies obtained from electronic model chemistries
Journal of Chemical Theory and Computation, 2010Co-Authors: I M Alecu, Jingjing Zheng, Yan Zhao, Donald G TruhlarAbstract:Optimized Scale Factors for calculating vibrational harmonic and fundamental frequencies and zero-point energies have been determined for 145 electronic model chemistries, including 119 based on approximate functionals depending on occupied orbitals, 19 based on single-level wave function theory, three based on the neglect-of-diatomic-differential-overlap, two based on doubly hybrid density functional theory, and two based on multicoefficient correlation methods. Forty of the Scale Factors are obtained from large databases, which are also used to derive two universal Scale Factor ratios that can be used to interconvert between Scale Factors optimized for various properties, enabling the derivation of three key Scale Factors at the effort of optimizing only one of them. A reduced Scale Factor optimization model is formulated in order to further reduce the cost of optimizing Scale Factors, and the reduced model is illustrated by using it to obtain 105 additional Scale Factors. Using root-mean-square errors ...
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computational thermochemistry Scale Factor databases and Scale Factors for vibrational frequencies obtained from electronic model chemistries
Journal of Chemical Theory and Computation, 2010Co-Authors: I M Alecu, Jingjing Zheng, Yan Zhao, Donald G TruhlarAbstract:Optimized Scale Factors for calculating vibrational harmonic and fundamental frequencies and zero-point energies have been determined for 145 electronic model chemistries, including 119 based on approximate functionals depending on occupied orbitals, 19 based on single-level wave function theory, three based on the neglect-of-diatomic-differential-overlap, two based on doubly hybrid density functional theory, and two based on multicoefficient correlation methods. Forty of the Scale Factors are obtained from large databases, which are also used to derive two universal Scale Factor ratios that can be used to interconvert between Scale Factors optimized for various properties, enabling the derivation of three key Scale Factors at the effort of optimizing only one of them. A reduced Scale Factor optimization model is formulated in order to further reduce the cost of optimizing Scale Factors, and the reduced model is illustrated by using it to obtain 105 additional Scale Factors. Using root-mean-square errors from the values in the large databases, we find that scaling reduces errors in zero-point energies by a Factor of 2.3 and errors in fundamental vibrational frequencies by a Factor of 3.0, but it reduces errors in harmonic vibrational frequencies by only a Factor of 1.3. It is shown that, upon scaling, the balanced multicoefficient correlation method based on coupled cluster theory with single and double excitations (BMC-CCSD) can lead to very accurate predictions of vibrational frequencies. With a polarized, minimally augmented basis set, the density functionals with zero-point energy Scale Factors closest to unity are MPWLYP1M (1.009), τHCTHhyb (0.989), BB95 (1.012), BLYP (1.013), BP86 (1.014), B3LYP (0.986), MPW3LYP (0.986), and VSXC (0.986).
Jingjing Zheng - One of the best experts on this subject based on the ideXlab platform.
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computational thermochemistry Scale Factor databases and Scale Factors for vibrational frequencies obtained from electronic model chemistries
Journal of Chemical Theory and Computation, 2010Co-Authors: I M Alecu, Jingjing Zheng, Yan Zhao, Donald G TruhlarAbstract:Optimized Scale Factors for calculating vibrational harmonic and fundamental frequencies and zero-point energies have been determined for 145 electronic model chemistries, including 119 based on approximate functionals depending on occupied orbitals, 19 based on single-level wave function theory, three based on the neglect-of-diatomic-differential-overlap, two based on doubly hybrid density functional theory, and two based on multicoefficient correlation methods. Forty of the Scale Factors are obtained from large databases, which are also used to derive two universal Scale Factor ratios that can be used to interconvert between Scale Factors optimized for various properties, enabling the derivation of three key Scale Factors at the effort of optimizing only one of them. A reduced Scale Factor optimization model is formulated in order to further reduce the cost of optimizing Scale Factors, and the reduced model is illustrated by using it to obtain 105 additional Scale Factors. Using root-mean-square errors ...
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computational thermochemistry Scale Factor databases and Scale Factors for vibrational frequencies obtained from electronic model chemistries
Journal of Chemical Theory and Computation, 2010Co-Authors: I M Alecu, Jingjing Zheng, Yan Zhao, Donald G TruhlarAbstract:Optimized Scale Factors for calculating vibrational harmonic and fundamental frequencies and zero-point energies have been determined for 145 electronic model chemistries, including 119 based on approximate functionals depending on occupied orbitals, 19 based on single-level wave function theory, three based on the neglect-of-diatomic-differential-overlap, two based on doubly hybrid density functional theory, and two based on multicoefficient correlation methods. Forty of the Scale Factors are obtained from large databases, which are also used to derive two universal Scale Factor ratios that can be used to interconvert between Scale Factors optimized for various properties, enabling the derivation of three key Scale Factors at the effort of optimizing only one of them. A reduced Scale Factor optimization model is formulated in order to further reduce the cost of optimizing Scale Factors, and the reduced model is illustrated by using it to obtain 105 additional Scale Factors. Using root-mean-square errors from the values in the large databases, we find that scaling reduces errors in zero-point energies by a Factor of 2.3 and errors in fundamental vibrational frequencies by a Factor of 3.0, but it reduces errors in harmonic vibrational frequencies by only a Factor of 1.3. It is shown that, upon scaling, the balanced multicoefficient correlation method based on coupled cluster theory with single and double excitations (BMC-CCSD) can lead to very accurate predictions of vibrational frequencies. With a polarized, minimally augmented basis set, the density functionals with zero-point energy Scale Factors closest to unity are MPWLYP1M (1.009), τHCTHhyb (0.989), BB95 (1.012), BLYP (1.013), BP86 (1.014), B3LYP (0.986), MPW3LYP (0.986), and VSXC (0.986).
Xianghong Cheng - One of the best experts on this subject based on the ideXlab platform.
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optimized multi position calibration method with nonlinear Scale Factor for inertial measurement units
Sensors, 2019Co-Authors: Zihui Wang, Xianghong ChengAbstract:Navigation grade inertial measurement units (IMUs) should be calibrated after Inertial Navigation Systems (INSs) are assembled and be re-calibrated after certain periods of time. The multi-position calibration methods with advantage of not requiring high-precision equipment are widely discussed. However, the existing multi-position calibration methods for IMU are based on the model of linear Scale Factors. To improve the precision of INS, the nonlinear Scale Factors should be calibrated accurately. This paper proposes an optimized multi-position calibration method with nonlinear Scale Factor for IMU, and the optimal calibration motion of IMU has been designed based on the analysis of sensitivity of the cost function to the calibration parameters. Besides, in order to improve the accuracy and robustness of the optimization, an estimation method on initial values is presented to solve the problem of setting initial values for iterative methods. Simulations and experiments show that the proposed method outperforms the calibration method without nonlinear Scale Factors. The navigation accuracy of INS can be improved by up to 17% in lab conditions and 12% in the moving vehicle experiment, respectively.
