Related papers: Improved Calculation of Vibrational Mode Lifetimes…
We propose here a formal foundation for practical calculations of vibrational mode lifetimes in solids. The approach is based on a recursion method analysis of the Liouvillian. From this we derive the lifetime of a vibrational mode in terms…
A recent proposal for practical calculation of vibrational mode lifetimes is tested on simple, low-dimensional anharmonic models. The proposed scheme approximates the mode lifetime in terms of ensemble averages of specific functions in…
We present calculations on the damping of a low-frequency adsorbate mode on a metal surface, namely the frustrated translation of Na on Cu(100). For the first time, vibrational lifetimes of excited adlayers are extracted from…
We propose a new method to characterize the spatial distribution of particles' vibrations in solids with much lower computational costs compared to the usual normal mode analysis. We excite the specific vibrational mode in a two dimensional…
Vibrational dynamics governs the fundamental properties of molecular crystals, shaping their thermodynamics, mechanics, spectroscopy, and transport phenomena. However desirable, the first-principles calculation of solid-state vibrations,…
Symmetry-determined nonlinear normal modes, which describe large-amplitude vibrations of diamond lattice, are studied by specific group-theoretical methods. For two of these modes, corresponding to vibrational state with and without…
We develop a formalism to directly evaluate the matrix of force constants within a Quantum Monte Carlo calculation. We utilize the matrix of force constants to accurately relax the positions of atoms in molecules and determine their…
We report a computational study of the anharmonicity of the vibrational modes of various individual fullerenes using the "moments method" [Y. Gao and M. Daw, Modelling Simul. Mater. Sci. Eng. 23 045002 (2015)] with a Tersoff-style potential…
We aim to automatize the identification of collective variables to simplify and speed up enhanced sampling simulations of conformational dynamics in biomolecules. We focus on anharmonic low-frequency vibrations that exhibit fluctuations on…
Vibrational density of states of a classical two-dimensional electron system obtained with a molecular-dynamics simulation is shown to have a peak in both solid and liquid phases. From an exact diagonalisation of the dynamical matrix, the…
The lifetime of two-vibron bound states in the overtone region of a one-dimensional anharmonic molecular lattice is investigated. The anharmonicity, introduced within an attractive Hubbard Hamiltonian for bosons, is responsible for the…
In the present paper the resonances of vibrational modes in one-dimensional random Morse lattice are found and analyzed. The resonance energy exchange is observed at some values of elongation. Resonance $2 \omega_1 = \omega_2$ is…
We present a rigorous and efficient approach to the calculation of classical lattice-dynamical quantities from simulations that do not require an explicit solution of the time evolution. We focus on the temperature-dependent vibrational…
At room temperature, low frequency vibrations at far-infrared frequencies are thermally excited ($k_B T > h \nu$) and not restricted to harmonic fluctuations around a single potential energy minimum. For folded proteins, these intrinsically…
The classical lattice dynamics of honeycomb lattices is studied in the harmonic approximation. Interactions between nearest neighbors are represented by springs connecting them. A short and necessary introduction of the lattice structure is…
We have developed a formulation of density functional perturbation theory for the calculation of vibrational frequencies in molecules and solids, which uses numerical atomic orbitals as a basis set for the electronic states. The (harmonic)…
The ^1{\Sigma}^+ electronic ground states of MgLi^+ and CaLi^+ molecular ions are investigated for their spectroscopic constants and properties such as the dipole- and quadrupole moments, and static dipole polarizabilities. The quadrupole…
The anharmonic decay rates of atomic vibrations in amorphous silicon (a-Si) and paracrystalline silicon (p-Si), containing small crystalline grains embedded in a disordered matrix, are calculated using realistic structural models. The…
Understanding the vibrational and thermal properties of amorphous solids is one of the most discussed and long-standing issues in condensed matter physics. Recent works have made significant steps towards understanding harmonic vibrational…
An accurate and easily extendable method to deal with lattice dynamics of solids is offered. It is based on first-principles molecular dynamics simulations and provides a consistent way to extract the best possible harmonic - or higher…