Journal ArticleDOI
Time-independent eigenstate-free calculation of vibronic spectra beyond the harmonic approximation
Taras Petrenko,Guntram Rauhut +1 more
TLDR
This work presents an alternative route in which the RWF is determined pointwise in a spectral range on the basis of the inhomogeneous Schrödinger equation using an iterative subspace method, in which explicit state-by-state calculations of vibrational eigenstates are bypassed.Abstract:
The calculation of vibronic spectra and resonance Raman intensities can be performed on the basis of the Raman wavefunction (RWF) formalism. In general, the well-known sum-over-states (SOS) and time-dependent methods can be applied for calculating the RWF. We present an alternative route in which the RWF is determined pointwise in a spectral range on the basis of the inhomogeneous Schrodinger equation using an iterative subspace method, in which explicit state-by-state calculations of vibrational eigenstates are bypassed. We study this approach within the framework of vibrational configuration interaction theory in conjunction with high-level electronic structure calculations for the multidimensional Born-Oppenheimer potential energy surface. The method benefits from an implicit account of interference effects between vibrational states, so that its computational cost correlates with the required resolution in the spectra. The accuracy and efficiency of the method with respect to comparable SOS calculations are tested for the simulation of the photoelectron spectra of ClO2, HS2−, ZnOH−, and Zn(H2O)+.read more
Citations
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Journal ArticleDOI
The Molpro quantum chemistry package.
Hans-Joachim Werner,Peter J. Knowles,Frederick R. Manby,Joshua A. Black,Klaus Doll,Andreas Heßelmann,Daniel Kats,Andreas Köhn,Tatiana Korona,David A. Kreplin,Qianli Ma,Thomas F. Miller,Alexander O. Mitrushchenkov,Kirk A. Peterson,Iakov Polyak,Guntram Rauhut,Marat Sibaev +16 more
TL;DR: Molpro as mentioned in this paper is a general purpose quantum chemistry software package with a long development history, originally focused on accurate wavefunction calculations for small molecules but now has many additional distinctive capabilities that include, inter alia, local correlation approximations combined with explicit correlation, highly efficient implementations of single-reference correlation methods, robust and efficient multireference methods for large molecules, projection embedding, and anharmonic vibrational spectra.
Journal ArticleDOI
A new efficient method for the calculation of interior eigenpairs and its application to vibrational structure problems.
Taras Petrenko,Guntram Rauhut +1 more
TL;DR: An iterative subspace method that targets the eigenvectors with significant contributions to a given reference vector and is based on the optimality condition for the residual norm corresponding to the error in the solution vector is proposed.
Journal ArticleDOI
A General Approach for Calculating Strongly Anharmonic Vibronic Spectra with a High Density of States: The X̃2B1 ← X̃1A1 Photoelectron Spectrum of Difluoromethane.
Taras Petrenko,Guntram Rauhut +1 more
TL;DR: A time-independent eigenstate-free Raman wave function approach is used to calculate the entire spectrum of difluoromethane and the calculated spectrum is in very close agreement with experimental results.
Dissertation
Estudo numérico do espectro Raman ressonante anarmônico de moléculas diatômicas
TL;DR: In this article, the vibrational problem was solved through the Modified Variational Quantum Monte Carlo (MVQMC) simulation and the Vibrational Configurations Interaction (VCI) methods.
Journal ArticleDOI
Refined analysis of the X̃ 2A2←X̃ 1A1 photoelectron spectrum of furan
Taras Petrenko,Guntram Rauhut +1 more
TL;DR: Individual vibronic transitions with the most significant Franck-Condon factors were determined by the recently developed residual-based algorithm for the calculation of eigenpairs in conjunction with the formalism of contracted invariant Krylov subspaces.
References
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Journal ArticleDOI
An iteration method for the solution of the eigenvalue problem of linear differential and integral operators
TL;DR: In this article, a systematic method for finding the latent roots and principal axes of a matrix, without reducing the order of the matrix, has been proposed, which is characterized by a wide field of applicability and great accuracy, since the accumulation of rounding errors is avoided, through the process of minimized iterations.
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Journal ArticleDOI
Time‐dependent approach to semiclassical dynamics
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Journal ArticleDOI
Systematically convergent basis sets for explicitly correlated wavefunctions: the atoms H, He, B-Ne, and Al-Ar.
TL;DR: The new basis sets have been optimized for use with explicitly correlated F12 methods and are shown to yield much improved convergence toward the complete basis set limit in MP2-F12/3C calculations on several small molecules involving elements of both the first and second row.
Journal ArticleDOI
Systematically convergent basis sets for transition metals. II. Pseudopotential-based correlation consistent basis sets for the group 11 (Cu, Ag, Au) and 12 (Zn, Cd, Hg) elements
TL;DR: In this paper, a series of basis sets designed for valence-only and outer-core electron correlation are presented, as well as these sets augmented by additional diffuse functions for the accurate description of negative ions and weak interactions.
Related Papers (5)
Systematically convergent basis sets for explicitly correlated wavefunctions: the atoms H, He, B-Ne, and Al-Ar.
Toward large scale vibrational configuration interaction calculations.
Michael Neff,Guntram Rauhut +1 more