Surface reactions with oxygen are a fundamental cause of the degradation phosphorene. Using first-principles calculations, we show that for each atom adsorbed onto phosphorene there is an energy release about 2 eV. Although most stable forms electrically inactive and lead only to minor distortions lattice, low metastable which introduce deep donor and/or acceptor levels in gap. We also propose mechanism oxidation involving reactive dangling atoms suggest increase hydrophilicity

Ultrathin black phosphorus, or phosphorene, is the second known elementary two-dimensional material that can be exfoliated from a bulk van der Waals crystal. Unlike graphene it semiconductor with sizeable band gap and its excellent electronic properties make attractive for applications in transistor, logic, optoelectronic devices. However, also first widely investigated two dimensional to undergo degradation upon exposure ambient air. Therefore passivation method required study intrinsic...

Infrared predissociation spectra of water clusters have been measured in the frequency range 3000–3800 cm−1 using a molecular beam–color center laser apparatus. The transition from spectrum resembling that liquid to dimer is clearly seen. Detailed theoretical analyses normal mode theory, local and quantum simulation method are used interpret terms potential surface includes both intramolecular intermolecular degrees freedom.

We show that oxidation of phosphorene can lead to the formation a new family planar (2D) and tubular (1D) oxides sub-oxides, most them insulating. This confers black phosphorus native oxide be used as barrier material protective layer. Further, bandgap depends on oxygen concentration, suggesting controlled means engineer bandgap. For saturated composition, P$_2$O$_5$, both phases have large energy about 8.5eV, are transparent in near UV. These two forms predicted same enthalpy...

We show how the dynamically nonlocal formulation of classical nuclear motion in presence quantal electronic transitions presented many years ago by P. Pechukas [Phys. Rev. 181, 166 (1969); 174 (1969)] can be localized time using dependent perturbation theory to give an impulsive force which acts when trajectories hop between surfaces. The action this is completely equivalent adjusting velocities direction nonadiabatic coupling vector so as conserve energy, a procedure widely used surface...

The behavior of an excess electron in helium (at T=309 K) and xenon K T=248 is studied over a range fluid densities (ρ*=ρσ3=0.1–0.9). A path integral Monte Carlo technique used to model the ‘‘quantum’’ which interacts through pseudopotentials with ‘‘classical’’ solvent particles. In helium, becomes confined cavity behaves like particle spherical box. We observe contrasting more polarizable where exists ‘‘quasifree’’ state. variety equilibrium properties are presented characterize structure...

This article reviews recent progress in the theoretical modeling of excitation energy transfer (EET) processes natural light harvesting complexes. The iterative partial linearized density matrix path-integral propagation approach, which involves both forward and backward electronic degrees freedom together with a linearized, short-time approximation for nuclear freedom, provides an accurate efficient way to model nonadiabatic quantum dynamics at heart these EET processes. Combined recently...

An approach for treating dissipative, non-adiabatic quantum dynamics in general model systems at finite temperature based on linearizing the density matrix evolution forward-backward path difference environment degrees of freedom is presented. We demonstrate that can capture both short time coherent and long thermal equilibration an application to excitation energy transfer a photosynthetic light harvesting complex. Results are also presented some nonadiabatic scattering models which...

The most recent crystal structure of the Fenna–Matthews–Olson (FMO) protein complex indicates presence an additional eighth chromophore, which has been proposed to serve as a link between chlorosome and remaining seven chromophores. Here, we investigate implications this scenario through numerical calculations with generalized Bloch–Redfield (GBR) equation noninteracting blip approximation (NIBA). It is shown that oscillations often observed in population relaxation sites 1 2 may be...

Rather than incoherent hopping between chromophores, experimental evidence suggests that the excitation energy transfer in some biological light harvesting systems initially occurs coherently, and involves coherent superposition states which spreads over multiple chromophores separated by several nanometers. Treating such delocalized presence of decoherence dissipation arising from coupling to an environment is a significant challenge for conventional theoretical tools either use...

An accurate approach for computing intermolecular and intrachromophore contributions to spectral densities describe the electronic–nuclear interactions relevant modeling excitation energy transfer processes in light harvesting systems is presented. The based on molecular dynamics (MD) calculations of classical correlation functions long-range fluctuations a separate harmonic analysis single-point gradient quantum electron–intrachromophore vibrational couplings. A simple model also presented...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure and vibrational spectroscopy of the water dimer using quantum simulationD. F. Coker R. O. WattsCite this: J. Phys. Chem. 1987, 91, 10, 2513–2518Publication Date (Print):May 1, 1987Publication History Published online1 May 2002Published inissue 1 1987https://pubs.acs.org/doi/10.1021/j100294a015https://doi.org/10.1021/j100294a015research-articleACS PublicationsRequest reuse permissionsArticle Views545Altmetric-Citations137LEARN ABOUT THESE...

We present a new approach for calculating quantum time correlation functions systems whose dynamics exhibits relevant nonadiabatic effects. The method involves partial linearization of the full path-integral expression function written in mapping Hamiltonian formalism. Our analysis gives an algorithm which is both numerically efficient and accurate as we demonstrate test calculations on spin-boson model where find results good agreement with exact calculations. accuracy our comparable to...

In this paper we investigate the B state predissociation and subsequent geminate recombination of photoexcited iodine in liquid xenon using a coupled quantum-classical molecular dynamics method model Hamiltonian gained from diatomics-in-molecules semiempirical approach to excited electronic structure including spin-orbit coupling. We explore capabilities these techniques as applied studying realistic condensed phase reactions by comparing with available experimental data recent ultrafast...

We present a surface hopping trajectory method for studying nonadiabatic excess electronic relaxation in condensed systems. This approach is used to explore the after photoexciting an equilibrated electron dense fluid helium. survey different types of phenomena which are important relaxation. Very rapid diabatic processes common when nuclear dynamics provides only weak couplings between adiabatic states. generally case states localized regions space. find that mechanism strong coupling s-...

Powerful approximate methods for propagating the density matrix of complex systems that are conveniently described in terms electronic subsystem states and nuclear degrees freedom have recently been developed involve linearizing propagator difference between forward backward paths while keeping interference effects different mapping Hamiltonian formalism semi-classical mechanics. Here we demonstrate approaches to developing linearized approximation can yield a mean-field like which variables...

A site-dependent spectral density system-bath model of the Fenna-Matthews-Olsen (FMO) pigment-protein complex is developed using results from ground-state molecular mechanics simulations together with a partial charge difference for how long-range contributions to chromophore excitation energies fluctuate environmental configuration. discussion best consistently process energy fluctuation correlation functions calculated in these classical obtain reliable densities presented. The...

A partial linearized path integral approach is used to calculate the condensed phase electron transfer (ET) rate by directly evaluating flux-flux/flux-side quantum time correlation functions. We demonstrate for a simple ET model that this can reliably capture transition between non-adiabatic and adiabatic regimes as electronic coupling varied, while other commonly semi-classical methods are less accurate over broad range of couplings considered. Further, we show recovers Marcus turnover...

Recent experimental studies of both A and B state photoexcitation I2 the ensuing many-body dynamics in rare gas matrices by Apkarian co-workers are simulated using methods we presented an earlier work combining nonadiabatic molecular with semiempirical diatomics-in-molecules (DIM) excited electronic structure techniques. We extend our DIM to compute ion pair states I2-rare crystal system use these together a model configurational dependence dipole operator matrix elements calculate time...

We employ a surface hopping trajectory method to study the rapid nonadiabatic relaxation after an excess electron is injected in unperturbed fluid helium. Several distinctively different processes, characterized by their relative importance at times during localized equilibrium state are detailed. These processes include: Short time leakage from cavity cavity, exploring fluctuating solvent structure. This involves slow drifting of occupied through continuum levels. followed diabatic...