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Dec 10, 2024 | 
pubs.aip.org | Jinzhe Zeng |Miguel Jorge |Philipp Pracht
The dielectric function of a dipolar liquid exhibits a strong wavenumber dependence in the bulk homogeneous state. Such a behavior seems to suggest the possibility of a strong system size dependence of the dielectric constant (DC) of a nanoconfined liquid, although details have been revealed only recently.
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Dec 9, 2024 | 
pubs.aip.org | Jinzhe Zeng |Miguel Jorge |Philipp Pracht
The difference and similarity between the velocity- and position-Verlet integrators are discussed from the viewpoint of their Hamiltonian representations for both linear and nonlinear systems. For a harmonic oscillator, the exact Hamiltonians reveal that positional trajectories generated by the two integrators follow an identical second-order differential equation and thus can be matched by adjusting initial conditions.
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Dec 5, 2024 | 
pubs.aip.org | Jinzhe Zeng |Philipp Pracht
Topics
Density functional theory,
Electric fields,
Dielectric properties,
Polarizability,
Light scattering,
Depolarized Rayleigh spectroscopy,
Langevin dynamics
A recent paper on depolarized light scattering (DLS) intensities by Pabst and Blochowicz (PB)1 addresses important questions. However, it is overly dismissive of existing theory.
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Dec 4, 2024 | 
pubs.aip.org | Jinzhe Zeng |Miguel Jorge
In this article, we combine the periodic sinc basis set with a curvilinear coordinate system for electronic structure calculations. This extension allows for variable resolution across the computational domain, with higher resolution close to the nuclei and lower resolution in the inter-atomic regions. We address two key challenges that arise while using basis sets obtained by such a coordinate transformation.
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Dec 4, 2024 | 
pubs.aip.org | Jinzhe Zeng |Miguel Jorge
Calcium carbonate (CaCO ) plays a crucial role in the global carbon cycle, and its phase diagram is of significant scientific interest. We used molecular dynamics to investigate selected structural phase transitions of calcium carbonate.
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Oct 23, 2024 | 
pubs.aip.org | Los Alamos |Jinzhe Zeng |Y. A. Ran
As plutonium ages, several physical changes occur, including a reduction in density, changes in isotopic composition, nucleation and growth of helium bubbles, accumulation of deformation energy due to lattice defects and Frenkel pairs, an increase in yield stress, and a stiffening of the bulk modulus. These mechanisms have been the subject of much research during the past 20 years.
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Oct 23, 2024 | 
pubs.aip.org | Jinzhe Zeng |Y. A. Ran
Unlike one-dimensional polymers, the theoretical framework on the behaviors of two-dimensional (2D) polymers is far from completeness. In this study, we model single-layer flexible 2D polymers of different sizes and examine their scaling behaviors in solution, represented by R ∼ Lν, where R is the radius of gyration and L is the side length of a 2D polymer. We find that the scaling exponent ν is 0.96 for a good solvent and 0.64 for under poor solvent condition.
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Oct 22, 2024 | 
pubs.aip.org | Leninskie Gory |Jinzhe Zeng |Y. A. Ran
We describe the new method that can be useful for calculation of the excitation dynamics in large molecular arrays that can be split into compartments with weak exciton coupling between them. In this method, the dynamics within each compartment is evaluated nonperturbatively using hierarchical equations of motion (HEOM), whereas transfers between the exciton states belonging to different compartments are treated by the generalized Förster (gF) theory.
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Oct 18, 2024 | 
pubs.aip.org | Y. A. Ran |Jinzhe Zeng
The dynamics of molecular excitonic systems are complicated by a competition between electronic coupling (which drives delocalization) and vibrational-electronic (vibronic) interactions (which tend to encourage electronic localization). A particular challenge of molecular systems is that they typically possess a large number of independent vibrations, with frequencies often spanning the entire spectrum of relevant electronic energy gaps.
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Sep 13, 2024 | 
pubs.aip.org | Jinzhe Zeng
We derive an analytic expression of the non-equilibrium Fermi’s golden rule (NE-FGR) expression for a Holstein–Tavis–Cumming Hamiltonian, a universal model for many molecules collectively coupled to the optical cavity. These NE-FGR expressions capture the full-time-dependent behavior of the rate constant for transitions from polariton states to dark states.
