Parallel coupled perturbed CASSCF equations and analytic CASSCF second derivatives

Dudley, Timothy J.; Olson, Ryan M.; Schmidt, Michael W.; Gordon, Mark S.

doi:10.1002/jcc.20350

Cited by 30 publications

(28 citation statements)

References 49 publications

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“…Because analytic MCSCF Hessians are so computationally demanding, it is essential to implement them using a scalable algorithm. The scalability of the parallel MCSCF Hessian code in GAMESS [5] is illustrated in Figure 3, for the biologically important molecule 7-azaindole. This calculation employs a relatively modest basis set and a modest MCSCF active space.…”

Section: Casscf Hessiansmentioning

confidence: 99%

Scalable correlated electronic structure theory

Gordon

Ruedenberg

Schmidt

et al. 2006

J. Phys.: Conf. Ser.

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The approach taken in Ames to advance high-level electronic structure theory has been a combination of the development and implementation of new and novel methods with the continuing development of strategies to optimize scalable computing. This work summarizes advances on both fronts. Several new methods have been implemented under the Distributed Data Interface (DDI), most recently including analytic Hessians for both Hatree-Fock and CASSCF (complete active space self-consistent field) wavefunctions, gradients for restricted open shell second order perturbation theory, and the fragment molecular orbital method (FMO). Exciting new method developments include the FMO method and the CEEIS (Correlation Energy Extrapolation by Intrinsic Scaling) method for efficiently approaching the exact energy for atomic and molecular systems. Disciplines Chemistry Comments

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Section: Casscf Hessiansmentioning

confidence: 99%

Scalable correlated electronic structure theory

Gordon

Ruedenberg

Schmidt

et al. 2006

J. Phys.: Conf. Ser.

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“…[18][19][20][21] The linearscaling QM algorithms [22][23][24][25] have primarily been developed for energy and gradient evaluations; the efficiency of Hessian computations has also been improved. [26][27][28] Some fragment based approaches [29][30][31][32][33][34][35][36][37][38][39][40] feature analytic second derivatives. [41][42][43][44][45][46] The fragment molecular orbital (FMO) method [47][48][49][50][51] is a fragment-based approach.…”

Section: Introductionmentioning

confidence: 99%

Analytic second derivative of the energy for density functional theory based on the three-body fragment molecular orbital method

Nakata

Fedorov

Zahariev

et al. 2015

The Journal of Chemical Physics

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Analytic second derivatives of the energy with respect to nuclear coordinates have been developed for spin restricted density functional theory (DFT) based on the fragment molecular orbital method (FMO). The derivations were carried out for the three-body expansion (FMO3), and the two-body expressions can be obtained by neglecting the three-body corrections. Also, the restricted Hartree-Fock (RHF) Hessian for FMO3 can be obtained by neglecting the density-functional related terms. In both the FMO-RHF and FMO-DFT Hessians, certain terms with small magnitudes are neglected for computational efficiency. The accuracy of the FMO-DFT Hessian in terms of the Gibbs free energy is evaluated for a set of polypeptides and water clusters and found to be within 1 kcal/mol of the corresponding full (non-fragmented) ab initio calculation. The FMO-DFT method is also applied to transition states in SN2 reactions and for the computation of the IR and Raman spectra of a small Trp-cage protein (PDB: 1L2Y). Some computational timing analysis is also presented. KeywordsProteins, Polymers, Free energy, Raman spectra, Biochemical reactions Disciplines Chemistry CommentsThe following article appeared in Journal of Chemical Physics 142 (2015) Analytic second derivatives of the energy with respect to nuclear coordinates have been developed for spin restricted density functional theory (DFT) based on the fragment molecular orbital method (FMO). The derivations were carried out for the three-body expansion (FMO3), and the two-body expressions can be obtained by neglecting the three-body corrections. Also, the restricted HartreeFock (RHF) Hessian for FMO3 can be obtained by neglecting the density-functional related terms. In both the FMO-RHF and FMO-DFT Hessians, certain terms with small magnitudes are neglected for computational efficiency. The accuracy of the FMO-DFT Hessian in terms of the Gibbs free energy is evaluated for a set of polypeptides and water clusters and found to be within 1 kcal/mol of the corresponding full (non-fragmented) ab initio calculation. The FMO-DFT method is also applied to transition states in S N 2 reactions and for the computation of the IR and Raman spectra of a small Trp-cage protein (PDB: 1L2Y). Some computational timing analysis is also presented. C 2015 AIP Publishing LLC.[http://dx

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“…The transformed MO integrals are used in constructing B α matrices, but this transformation can be avoided in principle. The present implementation relies on an existing one, 35 and this part may be improved or rewritten in the future. In the opposite case, when the number of active orbitals (N act ) is greater than 10 for instance, it is the evaluations of the terms involving 4-RDM that are the most time-consuming, since the computational cost of these terms formally scales as O(N 9 act ).…”

Section: Methodsmentioning

confidence: 99%

Analytic First-Order Derivatives of Partially Contracted N-Electron Valence State Second-Order Perturbation Theory (PC-NEVPT2)

Nishimoto¹

2019

Preprint

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A balanced treatment of dynamic and static electron correlation is important in computational chemistry, and multireference perturbation theory (MRPT) is able to do this at a reasonable computational cost. In this paper, analytic first-order derivatives, speci cally gradients and dipole moments, are developed for a particular MRPT method, state-specific partially contracted n-electron valence state second-order perturbation theory (PC-NEVPT2). Only one linear equation needs to be solved for the derivative calculation if the Z-vector method is employed, which facilitates the practical application of this approach. Comparison of the calculated results with experimental geometrical parameters of O3 indicates excellent agreement, although the calculated results for O3- are slightly outside the experimental error bars. The 0-0 transition energies of various methylpyrimidines and trans-polyacetylene are calculated by performing geometry optimizations and seminumerical second-order geometrical derivative calculations. In particular, the deviations of 0-0 transition energies of trans-polyacetylene from experimental values are consistently less than 0.1 eV with PC-NEVPT2, indicating the reliability of the method. These results demonstrate the importance of adding dynamic electron correlation on top of methods dominated by static electron correlation and of developing analytic derivatives for highly accurate methods.

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Parallel coupled perturbed CASSCF equations and analytic CASSCF second derivatives

Cited by 30 publications

References 49 publications

Scalable correlated electronic structure theory

Scalable correlated electronic structure theory

Analytic second derivative of the energy for density functional theory based on the three-body fragment molecular orbital method

Analytic First-Order Derivatives of Partially Contracted N-Electron Valence State Second-Order Perturbation Theory (PC-NEVPT2)

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