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Understanding the correlation between electronic coupling and energetic stability of molecular crystal polymorphs: The instructive case of quinacridoneMay 17 2019A crucial factor determining charge transport in organic semiconductors is the electronic coupling between the molecular constituents, which is heavily influenced by the relative arrangement of the molecules. This renders quinacridone, with its multiple, ... More

Probing charge carrier movement in organic semiconductor thin films via nanowire conductance spectroscopyMay 17 2019Understanding the movement of charge within organic semiconducting films is crucial for applications in photo-voltaics and flexible electronics. We study the sensitivity of the electrical conductance of a silicon nanowire to changes of charge states within ... More

An efficient general methodology to explore the high-temperature frontier in f-block molecular nanomagnetsMay 16 2019One of the main roadblocks that still hampers the practical use of molecular magnets is their cryogenic working temperature. In the pursuit of rational strategies to design new nanomagnets with increasing blocking temperature, ab initio methodologies ... More

Excitons in two-dimensional atomic layer materials from time-dependent density functional theoryMay 16 2019Time-dependent density functional theory (TDDFT) has been applied to the calculation of absorption spectra for two-dimensional atomic layer materials. We reveal that the character of the first bright exciton state of bi-layer hexagonal boron nitride (h-BN) ... More

Quantifying the Plasmonic Character of Optical Excitations in a Molecular J-AggregateMay 16 2019The definition of plasmon at the microscopic scale is far from being understood. Yet, it is very important to recognize plasmonic features in optical excitations, as they can inspire new applications and trigger new discoveries by analogy with the rich ... More

Extension of the HCOOH and CO2 solid-state reaction network during the CO freeze-out stage: inclusion of H2COMay 16 2019Formic acid (HCOOH) and carbon dioxide (CO2) are simple species that have been detected in the interstellar medium. The solid-state formation pathways of these species under experimental conditions relevant to prestellar cores are primarily based off ... More

Excited states with selected CI-QMC: chemically accurate excitation energies and geometriesMay 16 2019We employ quantum Monte Carlo to obtain chemically accurate vertical and adiabatic excitation energies, and equilibrium excited-state structures for the small, yet challenging, formaldehyde and thioformaldehyde molecules. A key ingredient is a robust ... More

Reactivity of hydrated hydroxide anion cluster OH(H$_{2}$O)$_{n}^{-}$ with H and Rb: an ab initio studyMay 16 2019We present an theoretical investigation of the hydrated hydroxide anion clusters OH(H$_{2}$O)$_{n}^{-}$ and of the collisional complexes H-OH(H$_{2}$O)$_{n}^{-}$ and Rb-OH(H$_{2}$O)$_{n}^{-}$ (with n$=1-4$). The MP2 and CCSD(T) methods are used to calculate ... More

Revisiting $π$ Backbonding: The Influence of $d$ Orbitals on Metal-CO Bonds and Ligand Red ShiftsMay 16 2019The concept of $\pi$ backbonding is widely used to explain the complex stabilities and CO stretch frequency red shifts of transition metal carbonyls. We theoretically investigate a non-transition metal 18-electron carbonyl complex (Mg(CO)$_8$) and find ... More

Some Observations on the Performance of the Most Recent Exchange-Correlation Functionals for the Large and Chemically Diverse GMTKN55 BenchmarkMay 15 2019Benchmarks that span a broad swath of chemical space, such as GMTKN55, are very useful for assessing progress in the quest for more universal DFT functionals. We find that the WTMAD2 metrics for a great number of functionals show a clear "Jacob's Ladder ... More

Coupled Cluster Benchmark of New Density Functionals and Domain Pair Natural Orbital Methods: Mechanisms of Hydroarylation and Oxidative Coupling Catalyzed by Ru(II) Chloride CarbonylsMay 15 2019In the present work, we tested the performance of several new functionals for studying the mechanisms of concurrent reaction of hydroarylation and oxidative coupling catalyzed by Ru(II) chloride carbonyls. We find that DLPNO-CCSD(T) is an acceptable substitute ... More

Coherent multidimensional spectroscopy in the gas phaseMay 15 2019Recent work applying multidimentional coherent electronic spectroscopy at dilute samples in the gas phase is reviewed. The development of refined phase-cycling approaches with improved sensitivity has opened-up new opportunities to probe even dilute gas-phase ... More

Strong plasmonic fluorescence enhancement of individual plant light-harvesting complexesMay 15 2019Plasmonic coupling of metallic nanoparticles and adjacent pigments can dramatically increase the brightness of the pigments due to the enhanced local electric field. Here, we demonstrate that the fluorescence brightness of a single plant light-harvesting ... More

Non-Uniqueness of Parameters Extracted from Resonant Second-Order Nonlinear Optical SpectroscopiesMay 15 2019Experimental data from second-order nonlinear optical spectroscopies (SFG, DFG, and SHG) provide parameters relevant to the physical chemistry of interfaces and thin films. We show that there are in general 2 N or 2 N-1 equivalent sets of parameters to ... More

Nonlinear optical response of a gold surface in the visible range: A study by two-color sum-frequency generation spectroscopy. II. Model for metal nonlinear susceptibilityMay 15 2019We present a modeling of the nonlinear optical response of a metal surface in order to account for recent experimental results from two-color Sum-Frequency Generation experiments on gold. The model allows calculating the surface and bulk contributions, ... More

Quasi-Phase-Matching in Chiral MaterialsMay 15 2019The second-order nonlinear optical coefficients associated with chirality differ in sign for the two mirror-image forms (enantiomers) of a chiral material. Structures comprised of alternating stacks of the enantiomers can therefore be used for quasi-phase-matched ... More

Structural Characterization of an Ionic Liquid in bulk and in nano-confined environment from MD simulationsMay 15 2019This article contains data on structural characterization of the [C2Mim][NTf2] in bulk and in nano-confined environment obtained using MD simulations. These data supplement those presented in the paper Insights from Molecular Dynamics Simulations on Structural ... More

Breakdown of electroneutrality in nanoporesMay 14 2019Ion transport in extremely narrow nanochannels has gained increasing interest in recent years due to its unique physical properties, and the technological advances that allow us to study them. It is tempting to approach this regime with the tools and ... More

Multi-reference quantum chemistry protocol for simulating autoionization spectra: Test of ionization continuum models for the neon atomMay 14 2019In this contribution we present a protocol to evaluate partial and total Auger decay rates combining the restricted active space self-consistent field electronic structure method for the bound part and numerically obtained continuum orbitals in the single-channel ... More

Structural transition states explored with minimalist coarse grained models: applications to CalmodulinMay 14 2019Transitions between different conformational states are ubiquitous in proteins, being involved in signaling, catalysis and other fundamental activities in cells. However, modeling those processes is extremely difficult, due to the need of efficiently ... More

Non-adiabatic mass correction for excited states of molecular hydrogen: improvement for the outer-well $H\bar{H}\ ^1Σ_\mathrm{g}^+$ term valuesMay 14 2019The mass-correction function is evaluated for selected excited states of the hydrogen molecule within a single-state non-adiabatic treatment. Its qualitative features are studied under the avoided crossing of the $EF$ with the $GK$ state and also for ... More

Reactive molecular dynamics simulations of organometallic compound W(CO)6 fragmentationMay 14 2019Irradiation- and collision-induced fragmentation studies provide information about geometry, electronic properties and interactions between structural units of various molecular systems. Such knowledge brings insights into irradiation-driven chemistry ... More

A Variationally Computed IR Line List for the Methyl Radical CH$_3$May 14 2019We present the first variational calculation of a hot temperature ab initio line list for the CH$_3$ radical. It is based on a high level ab initio potential energy surface and dipole moment surface of CH$_3$ in the ground electronic state. The ro-vibrational ... More

Rovibronic spectra of molecules dressed by light fieldsMay 14 2019The theory of rovibronic spectroscopy of light-dressed molecules is presented within the framework of quantum mechanically treated molecules interacting with classical light fields. Numerical applications are demonstrated for the homonuclear diatomic ... More

An Effective Semiclassical Approach to IR SpectroscopyMay 14 2019We present a novel approach to calculate molecular IR spectra based on semiclassical molecular dynamics. The main advance from a previous semiclassical method [M. Micciarelli, R. Conte, J. Suarez, M. Ceotto J. Chem. Phys. 149, 064115 (2018)] consists ... More

Vibrational Stark Spectroscopy on Fluorobenzene with Quantum Cascade Laser Dual Frequency CombsMay 14 2019We demonstrate the performance of a dual frequency comb QCL spectrometer for the application of vibrational Stark spectroscopy. Measurements performed on fluorobenzene with the dual-comb spectrometer were compared to results obtained using a conventional ... More

Generalized swap networks for near-term quantum computingMay 13 2019The practical use of many types of near-term quantum computers requires accounting for their limited connectivity. One way of overcoming limited connectivity is to insert swaps in the circuit so that logical operations can be performed on physically adjacent ... More

Higher-order corrections to the Redfield equation with respect to the system-bath coupling based on the hierarchical equations of motionMay 13 2019The Redfield equation describes the dynamics of a quantum system weakly coupled to one or more reservoirs and is widely used in theory of open quantum system. However, the assumption of weak system-reservoir coupling is often not fully adequate and higher-order ... More

Alcohols on the rocks: solid-state formation in a H3CCCH + OH cocktail under dark cloud conditionsMay 13 2019A number of recent experimental studies have shown that solid-state complex organic molecules (COMs) can form under conditions that are relevant to the CO freeze-out stage in dense clouds. In this work, we show that alcohols can be formed well before ... More

Universal behaviour of diatomic halo states and the mass sensitivity of their propertiesMay 13 2019The scattering and spectroscopic properties of molecular halo states can serve as sensitive probes of the constancy of the electron-to-proton mass ratio $\beta=m_e/m_p$. Since halo states are formed by resonant $s$-wave interactions, their properties ... More

Theoretical rotation-vibration spectroscopy of {\it cis}- and {\it trans}-diphosphene (P$_2$H$_2$) and the deuterated species P$_2$HDMay 13 2019Growing astronomical interest in phosphorous (P) chemistry is stimulating the search for new interstellar P-bearing molecules; a task requiring detailed knowledge of the microwave and infrared molecular spectrum. In this work, we present comprehensive ... More

A simple self-interaction correction to RPA-like correlation energiesMay 12 2019The random phase approximation (RPA) is exact for the exchange energy of a many-electron ground state, but RPA makes the correlation energy too negative by about 0.5 eV/electron. That large short-range error, which tends to cancel out of iso-electronic ... More

Ammonium Fluoride as a Hydrogen-disordering Agent for IceMay 12 2019The removal of residual hydrogen disorder from various phases of ice with acid or base dopants at low temperatures has been a focus of intense research for many decades. As an antipode to these efforts, we now show using neutron diffraction that ammonium ... More

ExoMol Molecular linelists - XXXIII. The spectrum of Titanium OxideMay 11 2019Accurate line lists are crucial for correctly modelling a variety of astrophysical phenomena, including stellar photospheres and the atmospheres of extra-solar planets. This paper presents a new line database Toto for the main isotopologues of titanium ... More

Electrolytic Conversion of Bicarbonate into CO in a Flow CellMay 11 2019Electrochemical CO2 reduction offers a method to use renewable electricity to convert CO2 into CO and other carbon-based chemical building blocks. While nearly all studies rely on a CO2 feed, we show herein that aqueous bicarbonate solutions can also ... More

An Auxiliary-Field Quantum Monte Carlo Perspective on the Ground State of the Uniform Electron Gas: An Investigation with Spin-Restricted Hartree-Fock Trial WavefunctionsMay 10 2019We assess the utility of spin-restricted Hartree-Fock (RHF) trial wavefunctions in performing phaseless auxiliary-field quantum Monte Carlo (ph-AFQMC) on the uniform electron gas (UEG) model. This particular combination, RHF+ph-AFQMC, was found to be ... More

Complete basis set extrapolation of electronic correlation energies using the Riemann zeta functionMay 10 2019In this communication we present a method of complete basis set (CBS) extrapolation of correlation energies obtained with a systematic sequence of one-electron basis sets. Instead of fitting the finite-basis results with a certain functional form, we ... More

Specifics about Specific Ion Adsorption from Heterodyne-Detected Second Harmonic GenerationMay 10 2019Ion specific outcomes at aqueous interfaces remain among the most enigmatic phenomena in interfacial chemistry. Here, charged fused silica/water interfaces have been probed by homodyne- and heterodyne-detected (HD) second harmonic generation (SHG) spectroscopy ... More

General solutions for quantum dynamical systems driven by time-varying Hamiltonians: applications to NMRMay 10 2019Comprehending the dynamical behaviour of quantum systems driven by time-varying Hamiltonians is particularly difficult. Systems with as little as two energy levels are not yet fully understood. Since the inception of Magnus' expansion in 1954, no fundamentally ... More

Multiple orbital effects in laser-induced electron diffraction of aligned moleculesMay 09 2019Photoelectron Angular Distributions (PADs) resulting from 800 nm and 1300 nm strong field ionization of impulsively aligned CF$_3$I molecules were analyzed using time-dependent density functional theory (TDDFT). The normalized difference between the PADs ... More

A TDDFT-based Study on the Proton-DNA CollisionMay 09 2019The interaction of heavy charged particles with DNA is of interest for several areas, from hadrontherapy to aero-space industry. In this paper, a TD-DFT study on the interaction of a 4 keV proton with an isolated DNA base pair was carried out. Ehrenfest ... More

Atomic-resolution imaging of carbonyl sulfide by laser-induced electron diffractionMay 09 2019Measurements on the strong-field ionization of carbonyl sulfide molecules by short, intense, 2~\um wavelength laser pulses are presented from experiments where angle-resolved photoelectron distributions were recorded with a high-energy velocity map imaging ... More

Novel two-dimensional Ca-Cl crystals with metallicity, piezoelectric effect and room-temperature ferromagnetismMay 09 2019Recently we have reported the direct observation of two-dimensional (2D) Ca-Cl crystals on reduced graphene oxide (rGO) membranes, in which the calcium ions are only about monovalent (i.e. ~+1) and metallic rather than insulating properties are displayed ... More

Reaction blockading in charged-neutral excited-state chemistry at low collision energyMay 09 2019We study an excited atom-polar molecular ion chemical reaction (Ca$^*$ + BaCl$^+$) at low temperature by utilizing a hybrid atom-ion trapping system. The reaction rate and product branching fractions are measured and compared to model calculations as ... More

Local descriptors of dynamic and nondynamic correlationMay 08 2019Quantitatively accurate electronic structure calculations rely on the proper description of electron correlation. A judicious choice of the approximate quantum chemistry method depends upon the importance of dynamic and nondynamic correlation, which is ... More

Enzyme kinetics at the molecular levelMay 08 2019The celebrated Michaelis-Menten (MM) expression provides a fundamental relation between the rate of enzyme catalysis and substrate concentration. The validity of this classical expression is, however, restricted to macroscopic amounts of enzymes and substrates ... More

Nanoparticles actively fragment armored dropletsMay 07 2019Understanding the complexity of fragmentation processes is essential for regulating intercellular communication in mechanistic biology and developing novel bottom-up approaches in a large range of multiphase flow processes. In this context, self-fragmentation ... More

Many-Body Expanded Full Configuration Interaction. II. Strongly Correlated RegimeMay 07 2019In this second part of our series on the recently proposed many-body expanded full configuration interaction (MBE-FCI) method, we introduce the concept of multideterminantal expansion references. Through theoretical arguments and numerical validations, ... More

A General Approach for Multireference Ground and Excited States using Non-Orthogonal Configuration InteractionMay 07 2019A balanced description of ground and excited states is essential for the description of many chemical processes. However, few methods can handle cases where static correlation is present, and often these scale very unfavourably with system size. Recently, ... More

The spectrum of N$_2$ from 4,500 to 15,700 cm$^{-1}$ revisited with PGOPHERMay 07 2019Using a reference molecular atlas to ensure self-consistency of wavelength calibration is widespread practice. Boesch \& Reiners (Astronomy \& Astrophysics 582 A43 (2015)) reported a line list from a discharge of molecular nitrogen from 4500 to 11000 ... More

Foreign body reaction (immune respond) for artificial implants can be avoidedMay 07 2019Despite on great success with artificial implant for human body, the modern implants could not solve major health problems. The reason is an immune reaction of organism on artificial implant known as foreign body reaction. We have found a way to avoid ... More

Cage occupancies in nitrogen clathrate hydrates from Monte Carlo simulationsMay 07 2019Comparisons of Gibbs ensemble Monte Carlo simulations with experimental data for the cage occupancies in N2 clathrate hydrates are performed to assess the accuracy of such simulations, to refine the effective potentials employed, and to help interpret ... More

Mechanism of CO-oxidation on Pd/CeO2(100): The unique surface-structure of CeO2(100) and the role of peroxideMay 07 2019Understanding the atomic mechanism of low-temperature CO oxidation on a heterogeneous catalyst is challenging. We performed density functional theory (DFT) calculations to identify the surface structure and reaction mechanism responsible for low-temperature ... More

Local adsorption structure and bonding of porphine on Cu(111) before and after self-metalationMay 07 2019We have experimentally determined the lateral registry and geometric structure of free-base porphine (2H-P) and copper-metalated porphine (Cu-P) adsorbed on Cu(111), by means of energy-scanned photoelectron diffraction (PhD), and compared the experimental ... More

Solving the CH$_4^-$ riddle: the fundamental role of spin to explain metastable anionic methaneMay 07 2019When atoms or molecules exist in the form of stable negative ions, they play a crucial role in the gas phase chemistry. Determining the existence of such an ion, its internal energy and its stability are necessary prerequisites to analyze the role of ... More

Analytical modeling of micelle growth. 1. Chain-conformation free energy of binary mixed spherical, wormlike and lamellar micellesMay 06 2019Hypotheses: A quantitative molecular-thermodynamic theory of the growth of giant wormlike micelles of nonionic surfactants can be developed on the basis of a generalized model, which includes the classical 'phase separation' and 'mass action' models as ... More

Tuning hydrogen adsorption on graphene by gate voltageMay 06 2019In order to realize applications of hydrogen-adsorbed graphene, a main issue is how to control hydrogen adsorption/desorption at room temperature. In this study, we demonstrate the possibility to tune hydrogen adsorption on graphene by applying a gate ... More

Controlled exploration of chemical space by machine learning of coarse-grained representationsMay 06 2019The size of chemical compound space is too large to be probed exhaustively. This leads high-throughput protocols to drastically subsample and results in sparse and non-uniform datasets. Rather than arbitrarily selecting compounds, we systematically explore ... More

The Correlated Electronic States of a few Polycyclic Aromatic Hydrocarbons: A Computational StudyMay 06 2019In recent years Polycyclic Aromatic Hydrocarbons (PAHs) have been studied for their electronic properties as they are viewed as nanodots of graphene. They have also been of interest as functional molecules for applications such as light emitting diodes ... More

Direct CO2 Electroreduction from CarbonateMay 06 2019The process of CO2 valorization, all the way from capture of CO2 to its electrochemical upgrade, requires significant inputs in each of the capture, upgrade, and separation steps. The gas phase CO2 feed following the capture-and-release stage and into ... More

Analytical gradients and nonadiabatic couplings for the state-average density matrix renormalization group self-consistent field methodMay 04 2019We present analytical gradients and nonadiabatic couplings for a state-average density matrix renormalization group self-consistent-field (SA-DMRG-SCF) wavefunction. Our formalism follows closely the state-average complete active space self-consistent-field ... More

Quantum Chemistry as a Benchmark for Near-Term Quantum ComputersMay 04 2019We present a quantum chemistry benchmark for noisy intermediate-scale quantum computers that leverages the variational quantum eigensolver, active space reduction, a reduced unitary coupled cluster ansatz, and reduced density purification as error mitigation. ... More

QM/MM-MD analysis of dissociation of Ag+ and H+ mediated cytidinesMay 04 2019We report a biased QM/MM molecular dynamics study of the dissociation process of cytidine-cytidine complexes mediated by Ag+ or H+ ions. We performed calculations under real solvent conditions and obtained the free energy profiles (FEP) by thermodynamic ... More

Efficient Electrocatalytic Reduction of CO2 by Nitrogen-Doped Nanoporous Carbon-Carbon Nanotube Membranes - A Step Towards the Electrochemical CO2 RefineryMay 04 2019The search for earth abundant, efficient and stable electrocatalysts that can enable the chemical reduction of CO2 to value-added chemicals and fuels at an industrially relevant scale, is a high priority for the development of a global network of renewable ... More

A General Strategy for Determining Atom Connecting PositionsMay 04 2019The construction of images used in chain-of-state(CoS) methods for transition state(TS) locating and minimum energy path(MEP) searching needs initial and final state prepared in advance. However, while exploring a chemical reaction with CoS methods, the ... More

Motional Narrowing under Markovian and Non-Markovian Hopping Transitions in Inhomogeneous Broadened Absorption Line ShapeMay 04 2019Inspired by recent experiments showing a minimum of electron paramagnetic resonance (ESR/EPR) line width as a function of inverse temperature, we studied the motional narrowing effect by considering a combined model of carrier transitions and static dispersion ... More

The Chronus Quantum (ChronusQ) Software PackageMay 03 2019The Chronus Quantum (ChronusQ) software package is an open source (under the GNU General Public License v2) software infrastructure which targets the solution of challenging problems that arise in ab initio electronic structure theory. Special emphasis ... More

Efficient Formulation of Full Configuration Interaction Quantum Monte Carlo in a Spin Eigenbasis via the Graphical Unitary Group ApproachMay 03 2019We provide a spin-adapted formulation of the Full Configuration Interaction Quantum Monte Carlo (FCIQMC) algorithm, based on the Graphical Unitary Group Approach (GUGA), which enables the exploitation of SU(2) symmetry within this stochastic framework. ... More

Analysis of over-magnetization of elemental transition metal solids from the SCANMay 03 2019Recent investigations have found that the strongly constrained and appropriately normed (SCAN) meta-GGA exchange-correlation functional significantly over-magnetizes elemental Fe, Co, and Ni solids. For the paradigmatic case, bcc Fe, the error relative ... More

Atomistic scale analysis of the carbonization process for C/H/O/N-based polymers with the ReaxFF reactive force fieldMay 03 2019During the carbonization process of raw polymer precursors, graphitic structures can evolve. The presence of these graphitic structures affects mechanical properties of the carbonized carbon fibers. To gain a better understanding of the chemistry behind ... More

Efficient computation of the second-Born self-energy using tensor-contraction operationsMay 03 2019In the nonequilibrium Green's function approach, the approximation of the correlation self-energy at the second-Born level is of particular interest, since it allows for a maximal speed-up in computational scaling when used together with the Generalized ... More

Analytical modeling of micelle growth. 2. Molecular thermodynamics of mixed aggregates and scission energy in wormlike micellesMay 03 2019Hypotheses: Quantitative molecular-thermodynamic theory of the growth of giant wormlike micelles in mixed nonionic surfactant solutions can be developed on the basis of a generalized model, which includes the classical phase separation and mass action ... More

Beyond Walkers in Stochastic Quantum Chemistry: Reducing Error using Fast Randomized IterationMay 03 2019We introduce a family of methods for the full configuration interaction problem in quantum chemistry, based on the fast randomized iteration (FRI) framework [L.-H. Lim and J. Weare, SIAM Rev. 59, 547 (2017)]. These methods stochastically impose sparsity ... More

Projected Density Matrix Embedding Theory with Applications to the Two-Dimensional Hubbard ModelMay 02 2019Density matrix embedding theory (DMET) is a quantum embedding theory for strongly correlated systems. From a computational perspective, one bottleneck in DMET is the optimization of the correlation potential to achieve self-consistency, especially for ... More

The pH Dependence of Ultrafast Charge Dynamics in Graphene Oxide DispersionsMay 02 2019The pH dependence of emission from graphene oxide is believed to be due to the protonation of surface functional groups. In this study we use transient absorption spectroscopy to study the sub-picosecond charge dynamics in graphene oxide over a range ... More

Range-separated double-hybrid density-functional theory with coupled-cluster and random-phase approximationsMay 02 2019We construct range-separated double-hybrid schemes which combine coupled-cluster or random-phase approximations with a density functional based on a two-parameter Coulomb-attenuating-method-like decomposition of the electron-electron interaction. We find ... More

First principles study of the vibronic coupling in positively charged C$_{60}^+$May 01 2019The orbital vibronic coupling parameters for C$_{60}^{+}$ are derived by using density functional theory calculations with hybrid B3LYP functional. The obtained parameters tend to be stronger than the estimates within local density approximation. Based ... More

Hamiltonian symmetries in auxiliary-field quantum Monte Carlo calculations for electronic structureMay 01 2019We describe how to incorporate symmetries of the Hamiltonian into auxiliary-field quantum Monte Carlo calculations (AFQMC). Focusing on the case of Abelian symmetries, we show that the computational cost of most steps of an AFQMC calculation is reduced ... More

Analytical PAW Projector Functions for Reduced Bandwidth RequirementsMay 01 2019Large scale electronic structure calculations require modern high performance computing (HPC) resources and, as important, mature HPC applications that can make efficient use of those. Real-space grid-based applications of Density Functional Theory (DFT) ... More

Cavity Ring-down UV spectroscopy of the C$^2Σ^+$-X$^2Π$ electronic transition of CHMay 01 2019Rotationally resolved spectra of the C$^2\Sigma^+$-X$^2\Pi$ electronic system of the CH radical were measured using cavity ring-down spectroscopy in supersonically expanding, planar hydrocarbon plasma. The experimental conditions allowed the study of ... More

Cavity Ring-down UV spectroscopy of the C$^2Σ^+$-X$^2Π$ electronic transition of CHMay 01 2019May 02 2019Rotationally resolved spectra of the C$^2\Sigma^+$-X$^2\Pi$ electronic system of the CH radical were measured using cavity ring-down spectroscopy in supersonically expanding, planar hydrocarbon plasma. The experimental conditions allowed the study of ... More

Simulating conical intersection dynamics in the condensed phase with hybrid quantum master equationsApr 30 2019We present a framework for simulating the relaxation dynamics through a conical intersection of an open quantum system that combines a set of methods to approximate the motion of degrees of freedom with disparate time and energy scales. In the vicinity ... More

Targeting doubly-excited states with Equation of Motion Coupled Cluster theory restricted to double excitationsApr 30 2019The accurate description of doubly-excited states using conventional electronic structure methods is remarkably challenging, primarily because such excited states require the inclusion of doubly or higher excited configurations or the application of multi-reference ... More

Targeting excited states in all-trans polyenes with electron-pair statesApr 30 2019Wavefunctions restricted to electron pair states are promising models for strongly-correlated systems. Specifically, the pair Coupled Cluster Doubles (pCCD) ansatz allows us to accurately describe bond dissociation processes and heavy-element containing ... More

Modeling the electronic structures of the ground and excited states of the ytterbium atom and the ytterbium dimer: A modern quantum chemistry perspectiveApr 29 2019We present a comprehensive theoretical study of the electronic structures of the Yb atom and the Yb$_2$ molecule, respectively, focusing on their ground and lowest-lying electronically excited states. Our study includes various state-of-the-art quantum ... More

Quantum Control with Quantum Light of Molecular NonadiabaticityApr 29 2019Coherent control experiments in molecules are often done with shaped laser fields. The electric field is described classically and control over the time evolution of the system is achieved by shaping the laser pulses in the time or frequency domain. Moving ... More

A sensitive calorimetric technique to study energy (heat) exchange at the nano-scaleApr 29 2019Every time a chemical reaction occurs, an energy exchange between reactants and environment exists, which is defined as the enthalpy of the reaction. In the last decades, research has resulted in an increasing number of devices at the micro- or nano-scale. ... More

Enhanced screening and spectral diversity in many-body elastic scattering of excitons in two-dimensional hybrid metal-halide perovskitesApr 28 2019May 12 2019In two-dimensional hybrid organic-inorganic metal-halide perovskites, the intrinsic optical lineshape reflects multiple excitons with distinct binding energies, each dressed differently by the hybrid lattice. Given this complexity, a fundamentally far-reaching ... More

Enhanced screening and spectral diversity in many-body elastic scattering of excitons in two-dimensional hybrid metal-halide perovskitesApr 28 2019In two-dimensional hybrid organic-inorganic metal-halide perovskites, the intrinsic optical excitation lineshape reflects multiple excitons with distinct binding energies, which are dressed differently by the hybrid lattice. Given this complexity, a fundamentally ... More

Magnetic tuning of ultracold barrierless chemical reactionsApr 27 2019While attaining external field control of bimolecular chemical reactions has long been a coveted goal of physics and chemistry, the role of hyperfine interactions and dc magnetic fields in achieving such control has remained elusive. We develop an extended ... More

Low temperature scattering with the R-matrix method: argon-argon scatteringApr 26 2019Results for elastic atom-atom scattering are obtained as a first practical application of RmatReact, a new code for generating high-accuracy scattering observables from potential energy curves. RmatReact has been created in response to new experimental ... More

Improved population operators for multi-state nonadiabatic dynamics with the mixed quantum-classical mapping approachApr 26 2019The mapping approach addresses the mismatch between the continuous nuclear phase space and discrete electronic states by creating an extended, fully continuous phase space using a set of harmonic oscillators to encode the populations and coherences of ... More

Molecular simulation study of the heat capacity of metastable water between 100K and 300KApr 26 2019Molecular simulation study of the heat capacity of metastable water between 100K and 300K Molecular simulations have been used to study the heat capacity of metastable liquid water at low temperature adsorbed on a smooth surface. These calculations aim ... More

Observation of Kinetic Isotope Effect in Electrocatalysis with Fully Deuterated Ultrapure ElectrolytesApr 26 2019Kinetic isotope effect (KIE) is a common physicochemical effect to elucidate complicated microscopic reaction mechanism in biological, chemical and physical systems. Especially, the exchange of hydrogen to deuterium is a standard approach to investigate ... More

Emulating optical cycling centers in polyatomic moleculesApr 25 2019An optical cycling center (OCC) is a recently coined term to indicate two electronic states within a complex quantum object that can repeatedly experience optical laser excitation and spontaneous decay, while being well isolated from its environment. ... More

The Case of H$_2$C$_3$O Isomers, Revisited: Solving the Mystery of the Missing PropadienoneApr 25 2019To date, two isomers of H$_2$C$_3$O have been detected, namely, propynal (HCCCHO) and cylclopropenone (c-H$_2$C$_3$O). A third, propadienone (CH$_2$CCO), has thus far eluded observers despite the fact that it is the lowest in energy of the three. This ... More

An Improved Descriptor of Cluster Stability. Application to Small Carbon ClustersApr 25 2019The mass spectra of gas-phase clusters in cluster beams have a rich structure where the relative heights of the peaks compared to peaks corresponding to clusters of neighbor sizes reveal the stability of the clusters as a function of the size $N$. In ... More

An In Situ Surface-Enhanced Infrared Absorption Spectroscopy Study of Electrochemical CO2 Reduction: Selectivity Dependence on Surface C-Bound and O-Bound Reaction IntermediatesApr 25 2019The CO_{2} electro-reduction reaction (CORR) is a promising avenue to convert greenhouse gases into high-value fuels and chemicals, in addition to being an attractive method for storing intermittent renewable energy. Although polycrystalline Cu surfaces ... More

Static polarizability and hyperpolarizability in atoms and molecules through a Cartesian-grid DFTApr 25 2019Static electric response properties of atoms and molecules are reported within the real-space Cartesian grid implementation of pseudopotential Kohn-Sham (KS) density functional theory (DFT). A detailed systematic investigation is made for a representative ... More

Critical parameters and spherical confinement of H atom in screened Coulomb potentialApr 25 2019Critical parameters in three screened potentials, namely, Hulth\'en, Yukawa and exponential cosine screened Coulomb potential are reported. Accurate estimates of these parameters are given for each of these potentials, for all states having $n \leq 10$. ... More