Quasi-solid state microscopic dynamics in equilibrium classical liquids: Self-consistent relaxation theory

Theoretical and Mathematical Physics - In the framework of the concept of time correlation functions, we develop a self-consistent relaxation theory of the transverse collective particle dynamics...     

Pade spectroscopy of structural correlation functions: Application to liquid gallium

We propose the new method of fluid structure investigation based on numerical analytic continuation of structural correlation functions with Pade approximants. The method particularly allows extracting hidden structural features of disordered condensed matter systems from experimental diffraction data. The method has been applied to investigate the local order of liquid gallium, which has a non-trivial structure in both the liquid and solid states. Processing the correlation functions obtained from molecular dynamic simulations, we show the method proposed reveals non-trivial structural features of liquid gallium such as the spectrum of length-scales and the existence of different types of local clusters in the liquid.     

Microscopic collective dynamics of water

Data obtained on microscopic collective excitations in water by molecular dynamics simulation within the framework of the coarse-grained mW-model of the intermolecular interaction potential for water are reported. The calculated spectra of the dynamic structure factor and spectral densities of time correlation functions of longitudinal and transverse currents reveal the existence of propagating collective excitations of longitudinal and transverse polarization in water for a wide range of wavenumbers. The dynamics of fluctuations in the particle number density is analyzed within the framework of a microscopic theory that takes into account only the structural features of a system. The theoretically calculated data on the spectra of dynamic structure factor in a wavenumber range of 0.13–0.48 Å^–1 are in good agreement with the results of molecular dynamics simulation.     

Atomic collective excitations in liquid lead

The atomic dynamics of liquid lead at the temperature T = 600 K has been simulated on the basis of the embedded atom model potential (the “embedded” atom model making it possible to effectively take into account the many-particle interactions) in order to study the mechanisms of formation of the atomic collective excitations. Spectra of the dynamic structure factor S(k, ω) and the spectral densities of the time correlation functions of the longitudinal \(\tilde C_L\) (k, ω) and transverse \(\tilde C_T\) (k, ω) currents have been calculated for the wavenumber region 0.11 Å^?1 ≤ k ≤ 2.01 Å^?1. It has been established that the dynamics of density fluctuations is characterized by two dispersion “acoustic-like” branches of the longitudinal and transverse polarization.     

Electronic and Thermophysical Properties of Gas Hydrates: Ab Initio Simulation Results

Physics of the Solid State - Results of ab initio molecular-dynamic investigation of the electronic and thermophysical properties of methane hydrate with cubic structure sI are represented. The...     

Electrocrystallization of Supercooled Water in Confinement

Physics of the Solid State - The paper discusses the features of supercooled water thin film of width d = 3.97 nm contained by the perfect graphene layers and crystallizing under external...