Ab Initio Multiple Spawning:  Photochemistry from First Principles Quantum Molecular Dynamics

2000 ◽  
Vol 104 (22) ◽  
pp. 5161-5175 ◽  
Author(s):  
M. Ben-Nun ◽  
Jason Quenneville ◽  
Todd J. Martínez
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
First Principles ◽  
Quantum Molecular Dynamics ◽  
Multiple Spawning

scholarly journals Computational Methods for Ab Initio Molecular Dynamics

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Eric Paquet ◽  
Herna L. Viktor
Keyword(s):  
Molecular Dynamics ◽  
Quantum Mechanics ◽  
Ab Initio ◽  
First Principles ◽  
Density Functional ◽  
Path Integrals ◽  
Ab Initio Molecular Dynamics ◽  
Molecular Systems ◽  
Hartree Fock ◽  
Computational Perspective

Ab initio molecular dynamics is an irreplaceable technique for the realistic simulation of complex molecular systems and processes from first principles. This paper proposes a comprehensive and self-contained review of ab initio molecular dynamics from a computational perspective and from first principles. Quantum mechanics is presented from a molecular dynamics perspective. Various approximations and formulations are proposed, including the Ehrenfest, Born–Oppenheimer, and Hartree–Fock molecular dynamics. Subsequently, the Kohn–Sham formulation of molecular dynamics is introduced as well as the afferent concept of density functional. As a result, Car–Parrinello molecular dynamics is discussed, together with its extension to isothermal and isobaric processes. Car–Parrinello molecular dynamics is then reformulated in terms of path integrals. Finally, some implementation issues are analysed, namely, the pseudopotential, the orbital functional basis, and hybrid molecular dynamics.

scholarly journals SSAIMS—Stochastic-Selection Ab Initio Multiple Spawning for Efficient Nonadiabatic Molecular Dynamics

2020 ◽  
Vol 124 (30) ◽  
pp. 6133-6143 ◽  
Author(s):  
Basile F. E. Curchod ◽  
William J. Glover ◽  
Todd J. Martínez
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Multiple Spawning ◽  
Nonadiabatic Molecular Dynamics ◽  
Stochastic Selection

Classical versus ab initio structural relaxation: electronic excitations and optical properties of Ge nanocrystals embedded in a SiC matrix

2004 ◽  
Vol 832 ◽  
Author(s):  
Giancarlo Cappellini ◽  
H.-Ch. Weissker ◽  
D. De Salvator ◽  
J. Furthmüller ◽  
F. Bechstedt ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Optical Properties ◽  
Ab Initio ◽  
First Principles ◽  
Electronic Excitation ◽  
First Principle ◽  
Electronic Excitations ◽  
Combined Method ◽  
Classical Molecular Dynamics ◽  
Ge Nanocrystals

ABSTRACTWe discuss and test a combined method to efficiently perform ground- and excited-state calculations for relaxed structures using both a quantum first-principles approach and a classical molecular-dynamics scheme. We apply this method to calculate the ground state, the optical properties, and the electronic excitations of Ge nanoparticles embedded in a cubic SiC matrix. Classical molecular dynamics is used to relax the large-supercell system. First-principles quantum techniques are then used to calculate the electronic structure and, in turn, the electronic excitation and optical properties. The proposed procedure is tested with data resulting from a full first-principles scheme. The agreement is quantitatively discussed between the results after the two computational paths with respect to the structure, the optical properties, and the electronic excitations. The combined method is shown to be applicable to embedded nanocrystals in large simulation cells for which the first-principle treatment of the ionic relaxation is presently out of reach, whereas the electronic, optical and excitation properties can already be obtained ab initio. The errors incurred from the relaxed structure are found to be non-negligible but controllable.

Ab Initio Calculations for Grain Boundaries in Covalent Ceramics

1996 ◽  
Vol 458 ◽  
Author(s):  
Masanori Kohyama
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Grain Boundaries ◽  
First Principles ◽  
Localized States ◽  
Edge States ◽  
Bulk Diamond ◽  
First Time ◽  
Bulk Band

ABSTRACTAb initio calculations of grain boundaries in SiC have been performed for the first time by using the first-principles molecular dynamics (FPMD) method. Four-fold coordinated models of polar and non-polar interfaces of the {122}Σ = 9 boundary in SiC have been examined. Interfacial C-C and Si-Si wrong bonds have bond lengths and bond charges similar to those in bulk diamond and Si. The C-C bonds generate greatly localized states at the valence-band edges, which have features similar to the bulk band-edge states of diamond. The wrong bonds have significant effects on the properties of grain boundaries in SiC.

MULTIPHASE EQUATION OF STATE AND STRENGTH PROPERTIES OF BERYLLIUM FROM AB INITIO AND QUANTUM MOLECULAR DYNAMICS CALCULATIONS.

2008 ◽  
Author(s):  
G. Robert ◽  
A. Sollier ◽  
Ph. Legrand ◽  
Mark Elert ◽  
Michael D. Furnish ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Equation Of State ◽  
Ab Initio ◽  
Strength Properties ◽  
Quantum Molecular Dynamics ◽  
Molecular Dynamics Calculations

Melting and lattice dynamics of sodium at high pressures. Ab initio quantum molecular-dynamics analysis

2012 ◽  
Vol 115 (1) ◽  
pp. 105-111 ◽  
Author(s):  
S. V. Lepeshkin ◽  
M. V. Magnitskaya ◽  
N. L. Matsko ◽  
E. G. Maksimov
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Lattice Dynamics ◽  
High Pressures ◽  
Dynamics Analysis ◽  
Quantum Molecular Dynamics

scholarly journals Ab Initio Nonadiabatic Quantum Molecular Dynamics

2018 ◽  
Vol 118 (7) ◽  
pp. 3305-3336 ◽  
Author(s):  
Basile F. E. Curchod ◽  
Todd J. Martínez
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Quantum Molecular Dynamics

First-principles quantum molecular-dynamics study of the vibrations of icosahedralC60

1991 ◽  
Vol 44 (8) ◽  
pp. 4052-4055 ◽  
Author(s):  
G. B. Adams ◽  
J. B. Page ◽  
O. F. Sankey ◽  
K. Sinha ◽  
J. Menendez ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
First Principles ◽  
Quantum Molecular Dynamics
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