Journal ArticleDOI
Extended Born-Oppenheimer molecular dynamics
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TLDR
The proposed Lagrangian includes extended electronic degrees of freedom as auxiliary dynamical variables in addition to the nuclear coordinates and momenta to enable the application of higher-order symplectic or geometric integration schemes that are stable and energy conserving even under incomplete self-consistency convergence.Abstract:
A Lagrangian generalization of time-reversible Born-Oppenheimer molecular dynamics Niklasson et al. [Phys. Rev. Lett. 97, 123001 (2006)] is proposed. The formulation enables the application of higher-order symplectic or geometric integration schemes that are stable and energy conserving even under incomplete self-consistency convergence. It is demonstrated how the accuracy is improved by over an order of magnitude compared to previous formulations at the same level of computational cost. The proposed Lagrangian includes extended electronic degrees of freedom as auxiliary dynamical variables in addition to the nuclear coordinates and momenta. While the nuclear degrees of freedom propagate on the Born-Oppenheimer potential energy surface, the extended auxiliary electronic degrees of freedom evolve as a harmonic oscillator centered around the adiabatic propagation of the self-consistent ground state.read more
Citations
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DFTB+, a software package for efficient approximate density functional theory based atomistic simulations
Benjamin Hourahine,Bálint Aradi,Volker Blum,Franco P. Bonafé,A. Buccheri,Cristopher Camacho,C. Cevallos,M. Y. Deshaye,Traian Dumitrica,Adriel Dominguez,Sebastian Ehlert,Marcus Elstner,T. van der Heide,Jan Hermann,Stephan Irle,Julian J. Kranz,Christof Köhler,Tim Kowalczyk,Tomáš Kubař,I. S. Lee,Vitalij Lutsker,Reinhard J. Maurer,Seung Kyu Min,Izaac Mitchell,Christian F. A. Negre,Thomas A. Niehaus,Anders M. N. Niklasson,Alister J. Page,Alessandro Pecchia,G. Penazzi,M. P. Persson,Jan Řezáč,Cristián G. Sánchez,Michael Sternberg,Martin Stöhr,F. Stuckenberg,Alexandre Tkatchenko,Victor Yu,Thomas Frauenheim +38 more
TL;DR: An overview of the recently developed capabilities of the DFTB+ code is given, demonstrating with a few use case examples, and the strengths and weaknesses of the various features are discussed, to discuss on-going developments and possible future perspectives.
Journal ArticleDOI
Electronic Absorption Spectra from MM and ab Initio QM/MM Molecular Dynamics: Environmental Effects on the Absorption Spectrum of Photoactive Yellow Protein
TL;DR: It is shown that 40 or more surrounding water molecules must be included in the QM region in order to obtain converged excitation energies of the solvated PYP chromophore.
Journal ArticleDOI
Car–Parrinello molecular dynamics
TL;DR: The Born-Oppenheimer (BO) method as discussed by the authors is based on the same basic principles and can be derived from the same Lagrange function as the Car-Parrinello (CP) method.
Journal ArticleDOI
Modified Ehrenfest Formalism for Efficient Large-Scale ab initio Molecular Dynamics.
Xavier Andrade,Andrea Castro,David Zueco,J. L. Alonso,Pablo Echenique,Fernando Falceto,Angel Rubio +6 more
TL;DR: It is shown that the automatically enforced orthogonalization is of fundamental importance for large systems because not only it improves the scaling of the approach with the system size but it also allows for an additional very efficient parallelization level.
Journal ArticleDOI
Extended Lagrangian Born-Oppenheimer molecular dynamics with dissipation.
Anders M. N. Niklasson,Peter Steneteg,Anders Odell,Nicolas Bock,Matt Challacombe,C. J. Tymczak,Erik Holmström,Guishan Zheng,Valéry Weber +8 more
TL;DR: The approach corresponds to a Langevin-like dynamics for the electronic degrees of freedom with internal numerical error fluctuations and external, approximately energy conserving, dissipative forces, by tuning the dissipation to balance the numerical fluctuations.
References
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Book
Simulating Hamiltonian Dynamics
TL;DR: Geometric integrators as mentioned in this paper are time-stepping methods, designed such that they exactly satisfy conservation laws, symmetries or symplectic properties of a system of differential equations.
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