Latest in physics.chem-ph

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Spectra of the D2O dimer in the O-D fundamental stretch region: vibrational dependence of tunneling splittings and lifetimesMar 15 2019The fundamental O-D stretch region (2600 - 2800 cm-1) of the fully deuterated water dimer, (D2O)2, is studied using a pulsed supersonic slit jet source and a tunable optical parametric oscillator source. Relatively high spectral resolution (0.002 cm-1) ... More
Kinetics and mechanism of gold nanoparticle growth studied via optical extinction spectroscopy and computational modelingMar 14 2019The successful design of nanoparticle synthesis protocols requires insight from mechanistic models, whose development relies on the availability of experimental data. For this purpose, optical extinction spectroscopy (OES) is rarely used in spite of being ... More
Diffusion dynamics of supercooled water modeled with the cage-jump motion and hydrogen-bond rearrangementMar 14 2019The slow dynamics of glass-forming liquids is generally ascribed to the cage-jump motion. In the cage-jump picture, a molecule remains in a cage formed by neighboring molecules, and after a sufficiently long time, it jumps to escape from the original ... More
Explicitly correlated wavefunctions of the ground state and the lowest quintuplet state of carbon atomMar 14 2019Variational, nonrelativisitic energies have been calculated for the ground state ($^3P_g$) and the lowest quintuplet state ($^5S_u$) of the carbon atom, with wavefunctions expressed in the basis of symmetry-projected, explicitly correlated Gaussian (ECG) ... More
On the formalization of Asynchronous First Passage AlgorithmsMar 14 2019The formalization of First Passage schemes is revisited and the emerging of a conceptual contradiction is underlined. We then show why, despite such a contradiction, the numerical results are not explicitly affected. Through a different formalization ... More
Nanoscale domains in ionic liquids: A statistical mechanics definition for molecular dynamics studiesMar 14 2019One of the many open questions concerning Ionic Liquids (ILs) is the existence of nanoscale supramolecular domains which characterize the bulk. The hypothesis of their existence does not meet a general consensus since their definition seems to be based ... More
Analytical Gradients for Projection-Based Wavefunction-in-DFT EmbeddingMar 14 2019Projection-based embedding provides a simple, robust, and accurate approach for describing a small part of a chemical system at the level of a correlated wavefunction method while the remainder of the system is described at the level of density functional ... More
Decoding quantum errors with subspace expansionsMar 14 2019With the rapid developments in quantum hardware comes a push towards the first practical applications on these devices. While fully fault-tolerant quantum computers may still be years away, one may ask if there exist intermediate forms of error correction ... More
Particle-particle ladder based basis-set corrections applied to atoms and molecules using coupled-cluster theoryMar 13 2019Mar 14 2019We investigate the basis-set convergence of coupled cluster electronic correlation energies using a recently proposed finite basis-set correction technique. The correction is applied to atomic and molecular systems and is based on a diagrammatically decomposed ... More
Particle-particle ladder based basis-set corrections applied to atoms and molecules using coupled-cluster theoryMar 13 2019We investigate the basis-set convergence of coupled cluster electronic correlation energies using a recently proposed finite basis-set correction technique. The correction is applied to atomic and molecular systems and is based on a diagrammatically decomposed ... More
On the duality of ring and ladder diagrams and its importance for many-electron perturbation theoriesMar 13 2019Mar 14 2019We present a diagrammatic decomposition of the transition pair correlation function for the uniform electron gas. We demonstrate explicitly that ring and ladder diagrams are dual counterparts that capture significant long- and short-ranged interelectronic ... More
Emissivity of Ammonia IceMar 12 2019Bodies in the outer Solar System may consist of, or be covered by, solid ammonia. Their temperature depends on its emissivity. We calculate that emissivity as a function of frequency, angle and polarization and convolve it with a Planck function to obtain ... More
Efficient geometric integrators for nonadiabatic quantum dynamics in the diabatic basisMar 12 2019The split-operator algorithm combined with the dynamic Fourier method is a popular approach for quantum dynamics in systems with separable kinetic and potential energies because it is explicit, easy to implement, and preserves many geometric invariants ... More
Few layer 2D pnictogens catalyze the alkylation of soft nucleophiles with estersMar 12 2019Group 15 elements in zero oxidation state (P, As, Sb and Bi), also called pnictogens, are rarely used in catalysis due to the difficulties associated in preparing well-structured and stable materials. Here, we report on the synthesis of highly exfoliated, ... More
Finite Hydrogenic molecular chain H$_3$ and ion H$_2^-$ exist in a strong magnetic fieldMar 12 2019The existence and stability of the linear hydrogenic chain H$_3$ and H${}_2^-$ in a strong magnetic field is established. Variational calculations for H$_3$ and H${}_2^-$ are carried out in magnetic fields in the range $10^{11}\leq B \leq 10^{13}\,$G ... More
Accelerated estimation of long-timescale kinetics by combining weighted ensemble simulation with Markov model "microstates" using non-Markovian theoryMar 12 2019The weighted ensemble (WE) simulation strategy can provide unbiased sampling of non-equilibrium processes, such as molecular folding or binding. Once converged to steady state, exact kinetics can be extracted from any discrete clustering of the configuration ... More
Propagation of maximally localized Wannier functions in real-time TDDFTMar 11 2019Real-time, time-dependent density functional theory (RT-TDDFT) has gained popularity as a first-principles approach to study a variety of excited-state phenomena such as optical excitations and electronic stopping. Within RT-TDDFT simulations, the gauge ... More
Understanding the Methyl-TROSY effect over a wide range of magnetic fieldsMar 11 2019The use of relaxation interference in the methyl Transverse Relaxation-Optimized SpectroscopY (TROSY) experiment has opened new avenues for the study of large proteins and protein assemblies in nuclear magnetic resonance. So far, the theoretical description ... More
Understanding the Methyl-TROSY effect over a wide range of magnetic fieldsMar 11 2019Mar 12 2019The use of relaxation interference in the methyl Transverse Relaxation-Optimized SpectroscopY (TROSY) experiment has opened new avenues for the study of large proteins and protein assemblies in nuclear magnetic resonance. So far, the theoretical description ... More
Deep learning for molecular generation and optimization - a review of the state of the artMar 11 2019In the space of only a few years, deep generative modeling has revolutionized how we think of artificial creativity, yielding autonomous systems which produce original images, music, and text. Inspired by these successes, researchers are now applying ... More
Atomic energy mapping of neural network potentialMar 11 2019We show that the intelligence of the machine-learning potential arises from its ability to infer the reference atomic-energy function from a given set of total energies. By utilizing invariant points in the feature space at which the atomic energy has ... More
Ultra-fast Anisotropy Control in Photoelectron Spectra: A Two-Pulse StrategyMar 11 2019Coherence among rotational ion channels during photoionization is exploited to control the anisotropy of the resulting photoelectron angular distributions. The strategy refers to a robust and single parameter control using two ultra-short light pulses ... More
The Local Density Approximation in Density Functional TheoryMar 10 2019We give the first mathematically rigorous justification of the Local Density Approximation in Density Functional Theory. We provide a quantitative estimate on the difference between the grand-canonical Levy-Lieb energy of a given density (the lowest possible ... More
ZMP-SAPT: DFT-SAPT using ab initio DensitiesMar 08 2019Symmetry Adapted Perturbation Theory (SAPT) has become an important tool when predicting and analyzing intermolecular interactions. Unfortunately, DFT-SAPT, which uses Density Functional Theory (DFT) for the underlying monomers, has some arbitrariness ... More
K-shell Core Electron Excitations in the Electronic Stopping of Protons in WaterMar 07 2019Developing a detailed understanding for the role of core electron excitation in liquid water under proton irradiation has become important due to the growing use of proton beams in radiation oncology. Using a first-principles, non-equilibrium simulation ... More
Transfer Learning Using Ensemble Neural Nets for Organic Solar Cell ScreeningMar 07 2019Organic Solar Cells are a promising technology for solving the clean energy crisis in the world. However, generating candidate chemical compounds for solar cells is a time-consuming process requiring thousands of hours of laboratory analysis. For a solar ... More
Many body study of the Bohr-Weisskopf effect in the thallium atomMar 07 2019We report the relativistic coupled cluster study of the hyperfine structure and effect of the nuclear magnetization distribution (Bohr-Weisskopf effect) in the $6P_{1/2}$, $6P_{3/2}$ and $7S_{1/2}$ states of several Tl isotopes. It is shown that the Gaussian ... More
Robust Inference of Forces in Heterogeneous EnvironmentsMar 07 2019We devise a method to obtain a robust estimate of forces in a heterogeneous environment based on experimentally recorded trajectories. In particular, we focus on systems modeled by the heterogeneous overdamped Langevin equation. Here, the observed force ... More
Steady-state theory of interdigitated array of electrodes in confined spaces: Case of pure diffusion and reversible electrode reactionsMar 07 2019Analytical equations were found for interdigitated electrodes, which considered reversible electrode reactions and pure diffusion within confined spaces. A conformal transformation, obtained by the use of Jacobian elliptic functions, was applied to solve ... More
Evaluating 0-0 Energies with Theoretical Tools: a Short ReviewMar 06 2019For a given electronic excited state, the 0-0 energy ($T_0$ or $T_{00}$) is the simplest property allowing straightforward and physically-sound comparisons between theory and (accurate) experiment. However, the computation of 0-0 energies with \emph{ab ... More
Black Phosphorus/Palladium Nanohybrid: Unraveling the Nature of P-Pd Interaction and Application in Selective HydrogenationMar 06 2019The burgeoning interest in 2D black phosphorus (bP) contributes to expand its applications in countless fields. In the present study, 2D bP is used as a support for homogeneously dispersed palladium nanoparticles directly grown on it by a wet chemical ... More
Rotation-assisted wet-spinning of UV-cured gelatin fibres and nonwovensMar 06 2019Photoinduced network formation is an attractive strategy for designing water-insoluble gelatin fibres as medical device building blocks and for enabling late-stage property customisation. However, mechanically-competent, long-lasting filaments are still ... More
Chemical Potential of Integer Electron SystemsMar 06 2019A truly isolated atom always has an integer number of electrons. If placed in contact with a far-away metallic reservoir, a {\em range} of metallic chemical potentials $\mu$ will lead to an identical number of electrons, $N$, on the atom. We formulate ... More
MARTINI-based Coarse-grained Model for Poly(alpha-peptoid)sMar 05 2019In this paper, we present a new coarse-grained (CG) model for poly (alpha-peptoid)s that is compatible with the MARTINI CG FF. In the proposed model, CG poly (alpha-peptoid) is composed by a CG backbone (here we select polysarcosine as the backbone) and ... More
Temperature-dependent stability of polytypes and stacking faults in SiC: reconciling theory and experimentsMar 05 2019The relative stability of SiC polytypes, changing with temperature, has been considered a paradox for about thirty years, due to discrepancies between theory and experiments. Based on ab-initio calculations including van der Waals corrections, a temperature-dependent ... More
Interactions of benzene, naphthalene, and azulene with alkali-metal and alkaline-earth-metal atoms for ultracold studiesMar 04 2019We consider collisional studies of polyatomic aromatic hydrocarbon molecules immersed into ultracold atomic gases and investigate intermolecular interactions of exemplary benzene, naphthalene, and azulene with alkali-metal (Li, Na, K, Rb, Cs) and alkaline-earth-metal ... More
Using imaginary-time time-dependent density functional theory for robust convergence of ground statesMar 02 2019We transform the time-dependent density functional theory equations to imaginary time and use imaginary-time evolution as a reliable alternative to the self-consistent field (SCF) procedure for determining the Kohn-Sham (KS) ground state. We discuss the ... More
Stretched or noded orbital densities and self-interaction correction in density functional theoryMar 02 2019Semi-local approximations to the density functional for the exchange-correlation energy of a many-electron system necessarily fail for lobed one-electron densities, including not only the familiar stretched densities but also the less familiar but closely-related ... More
Zinc Electrode Shape-Change in Secondary Air Batteries: A 2D Modeling ApproachMar 01 2019Zinc-air batteries offer large specific energy densities, while relying on abundant and non-toxic materials. In this paper, we present the first multi-dimensional simulations of zinc-air batteries. We refine our existing theory-based model of secondary ... More
Thermodynamic Efficiency in Dissipative ChemistryFeb 28 2019Chemical processes in closed systems are poorly controllable since they always relax to equilibrium. Living systems avoid this fate and give rise to a much richer diversity of phenomena by operating under nonequilibrium conditions. Recent experiments ... More
Frequency comb spectroscopyFeb 28 2019A laser frequency combs is a broad spectrum composed of equidistant narrow lines. Initially invented for frequency metrology, such combs enable new approaches to spectroscopy over broad spectral bandwidths, of particular relevance to molecules. With optical ... More
First-principles prediction of potentials and space-charge layers in all-solid-state batteriesFeb 28 2019As all-solid-state batteries (SSBs) develop as an alternative to traditional cells, a thorough theoretical understanding of driving forces behind battery operation is needed. We present a fully first-principles-informed model of potential profiles in ... More
Crystallographic orientation dependence of work function: Carbon adsorption on Au surfacesFeb 28 2019We investigate the work function (WF) variation of different Au crystallographic surface orientations with carbon atom adsorption. Ab-initio calculations within density-functional theory are performed on carbon deposited (100), (110), and (111) gold surfaces. ... More
To Heat or not to Heat: a Study of the Performances of Iron Carbide Nanoparticles in Magnetic HeatingFeb 28 2019Heating magnetic nanoparticles with high frequency magnetic fields is a topic of interest for biological applications (magnetic hyperthermia) as well as for heterogeneous catalysis. This study shows why FeC NPs of similar structures and static magnetic ... More
Hypermetallic Polar Molecules for Precision MeasurementsFeb 27 2019Laser cooling is a powerful method to control molecules for applications in precision measurement, as well as quantum information, many-body physics, and fundamental chemistry. However, many optically-active metal centers in valence states which are promising ... More
Increasing the representation accuracy of quantum simulations of chemistry without extra quantum resourcesFeb 27 2019Proposals for near-term experiments in quantum chemistry on quantum computers leverage the ability to target a subset of degrees of freedom containing the essential quantum behavior, sometimes called the active space. This approximation allows one to ... More
Improved Fault-Tolerant Quantum Simulation of Condensed-Phase Correlated Electrons via TrotterizationFeb 27 2019Recent work has deployed linear combinations of unitaries techniques to significantly reduce the cost of performing fault-tolerant quantum simulations of correlated electron models. Here, we show that one can sometimes improve over those results with ... More
Real-Time Propagation TDDFT and Density Analysis for Exciton Couplings Calculations in Large SystemsFeb 27 2019Photo-active systems are characterized by their capacity of absorbing light energy and transforming it. Usually, more than one chromophore is involved in the light absorption and excitation transport processes in complex systems. Linear-Response Time-Dependent ... More
Atomistic structure learningFeb 27 2019One endeavour of modern physical chemistry is to use bottom-up approaches to design materials and drugs with desired properties. Here we introduce an atomistic structure learning algorithm (ASLA) that utilizes a convolutional neural network to build 2D ... More
DFT study of five-membered ring PAHsFeb 27 2019This work reports a 'Density Functional Theory' (DFT) calculation of PAH molecules with a five-member ring to determine the expected region of infrared features. It is highly possible that fullerene molecule might be originated from five-membered ring ... More
Resonant enhancement of thermally-activated chemical reactions via vibrational polaritonsFeb 26 2019In the regime of ensemble vibrational strong coupling (VSC), a large number $N\gg1$ of molecular transitions couple to each cavity mode, yielding two hybrid light-matter (polariton) modes, and a macroscopic reservoir of $N-1$ dark states whose chemical ... More
Room Temperature Quantum Coherence vs. Electron Transfer in a Rhodanine Derivative ChromophoreFeb 26 2019Mar 01 2019Understanding electron transfer in organic molecules is of great interest in quantum materials for light harvesting, energy conversion, and integration of molecules into solar cells. This, however, poses the challenge of designing specific optimal molecular ... More
Quantum Coherence vs. Electron Transfer in a Rhodanine Derivative ChromophoreFeb 26 2019Understanding electron transfer in organic molecules is of great interest in quantum materials for light harvesting, energy conversion, and integration of molecules into solar cells. This, however, poses the challenge of designing specific optimal molecular ... More
Onset of transverse (shear) waves in strongly-coupled Yukawa fluidsFeb 26 2019A simple practical approach to describe transverse (shear) waves in strongly-coupled Yukawa fluids is presented. Theoretical dispersion curves, based on hydrodynamic consideration, are shown to compare favorably with existing numerical results for plasma-related ... More
Benchmarking theory with an improved measurement of the ionization and dissociation energies of H$_2$Feb 25 2019The dissociation energy of H$_2$ represents a benchmark quantity to test the accuracy of first-principles calculations. We present a new measurement of the energy interval between the EF $^1\Sigma_g^+(v=0,N=1)$ state and the 54p1$_1$ Rydberg state of ... More
Confinement of high- and low-field-seeking Rydberg atoms using time-varying inhomogeneous electric fieldsFeb 25 2019Helium atoms in high- and low-field-seeking Rydberg states with linear and quadratic Stark shifts have been confined in two dimensions and guided over a distance of 150 mm using time-varying inhomogeneous electric fields. This was achieved with an electrode ... More
Strong deformation of ferrofluid-filled elastic alginate capsules in inhomogenous magnetic fieldsFeb 25 2019We present a new system based on alginate gels for the encapsulation of a ferrofluid drop, which allows us to create millimeter-sized elastic capsules that are highly deformable by inhomogeneous magnetic fields. We use a combination of experimental and ... More
Molybdenum oxide hole selective transport layer by hot wire oxidation-sublimation deposition for silicon heterojunction solar cellsFeb 25 2019In this article, a novel hot wire oxidation-sublimation deposition (HWOSD) technique was developed to prepare molybdenum oxide (MoOx) thin films with high quality. Silicon heterojunction (SHJ) solar cells with the HWOSD MoOx as a hole selective transport ... More
Kohn-Sham theory with paramagnetic currents: compatibility and functional differentiabilityFeb 25 2019Recent work has established Moreau-Yosida regularization as a mathematical tool to achieve rigorous functional differentiability in density-functional theory. In this article, we extend this tool to paramagnetic current-density-functional theory, the ... More
A direct comparison of high-speed methods for the numerical Abel transformFeb 24 2019The Abel transform is a mathematical operation that transforms a cylindrically symmetric three-dimensional (3D) object into its two-dimensional (2D) projection. The inverse Abel transform reconstructs the 3D object from the 2D projection. Abel transforms ... More
Electron transfer in confined electromagnetic fieldsFeb 24 2019The interaction between molecular (atomic) electron(s) and the vacuum field of a reflective cavity generates a significant interest thanks to the rapid developments in nanophotonics. Such interaction which lies within the realm of cavity quantum electrodynamic ... More
Linker-mediated phase behavior of DNA-coated colloidsFeb 24 2019Mar 14 2019The possibility of prescribing local interactions between nano- and microscopic components that direct them to assemble in a predictable fashion is a central goal of nanotechnology research. In this article we advance a new paradigm in which self-assembly ... More
Linker-mediated phase behavior of DNA-coated colloidsFeb 24 2019The possibility of prescribing local interactions between nano- and microscopic components that direct them to assemble in a predictable fashion is a central goal of nanotechnology research. In this letter we explore the self-assembly of DNA-functionalized ... More
Lattice Density-Functional Theory for Quantum ChemistryFeb 22 2019We propose a lattice density-functional theory for {\it ab initio} quantum chemistry or physics as a route to an efficient approach that approximates the full configuration interaction energy and orbital occupations for molecules with strongly-correlated ... More
Lattice Density-Functional Theory for Quantum ChemistryFeb 22 2019Feb 28 2019We propose a lattice density-functional theory for {\it ab initio} quantum chemistry or physics as a route to an efficient approach that approximates the full configuration interaction energy and orbital occupations for molecules with strongly-correlated ... More
PhysNet: A Neural Network for Predicting Energies, Forces, Dipole Moments and Partial ChargesFeb 22 2019In recent years, machine learning (ML) methods have become increasingly popular in computational chemistry. After being trained on appropriate ab initio reference data, these methods allow to accurately predict the properties of chemical systems, circumventing ... More
Deep Eutomic SolventsFeb 22 2019A new class of deep eutectic solvents are presented where one component of the system is inherently volatile, enabling a premeditated, auto-destructive capability which leads inexorably to a series of novel crystal structures. These deep eutomic solvents ... More
Quantum Package 2.0: An Open-Source Determinant-Driven Suite of ProgramsFeb 21 2019\textsc{Quantum Package} is an open-source programming environment for quantum chemistry specially designed for wave function methods. Its main goal is the development of determinant-driven selected configuration interaction (sCI) methods and multi-reference ... More
Intrinsic fluctuations of chemical reactions with different approachesFeb 21 2019The Brusselator model are used for the study of the intrinsic fluctuations of chemical reactions with different approaches. The equilibrium states of systems are assumed to be spirally stable in mean-field description, and two statistical measures of ... More
On construction of projection operatorsFeb 21 2019The problem of construction of projection operators on eigen-subspaces of symmetry operators is considered. This problem arises in many approximate methods for solving time-independent and time-dependent quantum problems, and its solution ensures proper ... More
Numerical Method for Nonlinear Optical Spectroscopies: Ultrafast Ultrafast SpectroscopyFeb 21 2019We outline a novel numerical method, called Ultrafast Ultrafast (UF$^2$), for calculating the $n^\text{th}$-order wavepackets required for calculating n-wave mixing signals. The method is simple to implement, and we demonstrate that it is computationally ... More
Numerical Method for Nonlinear Optical Spectroscopies: Ultrafast Ultrafast SpectroscopyFeb 21 2019Mar 01 2019We outline a novel numerical method, called Ultrafast Ultrafast (UF$^2$), for calculating the $n^\text{th}$-order wavepackets required for calculating n-wave mixing signals. The method is simple to implement, and we demonstrate that it is computationally ... More
A finite field approach to solving the Bethe Salpeter equationFeb 21 2019We present a method to compute optical spectra and exciton binding energies of molecules and solids based on the solution of the Bethe-Salpeter equation (BSE) and the calculation of the screened Coulomb interaction in finite field. The method does not ... More
Simulation of many-electron systems that exchange matter with the environmentFeb 20 2019The computational treatment of many-electron systems capable of exchanging {electrons and nuclei} with the environment represents one of the outermost frontiers in simulation methodology. The exchanging process occurs in a large variety of natural and ... More
On the Probability Density of the Nuclei in a Vibrationally Excited MoleculeFeb 20 2019For localized and oriented vibrationally excited molecules, the one-body probability density of the nuclei (one-nucleus density) is studied. Like the familiar and widely used one-electron density that represents the probability of finding an electron ... More
Modeling and analyzing a photo-driven molecular motor system: Ratchet dynamics and non-linear optical spectraFeb 20 2019A light-driven molecular motor system is investigated using a multi-state Brownian ratchet model described by a single effective coordinate with multiple electronic states in a dissipative environment. The rotational motion of the motor system is investigated ... More
All-electron density functional calculations for electron and nuclear spin interactions in molecules and solidsFeb 20 2019The interaction between electronic and nuclear spins in the presence of external magnetic fields can be described by a spin Hamiltonian, with parameters obtained from first principles, electronic structure calculations. We describe an approach to compute ... More
Molecular dynamics of open systems: construction of a mean-field particle reservoirFeb 19 2019The simulation of open molecular systems requires explicit or implicit reservoirs of energy and particles. Whereas full atomistic resolution is desired in the region of interest, there is some freedom in the implementation of the reservoirs. Here, we ... More
Gas-phase structural isomer identification by Coulomb explosion of aligned moleculesFeb 19 2019The gas-phase structures of four difluoroiodobenzene and two dihydroxybromobenzene isomers were identified by correlating the emission angles of atomic fragment ions created following femtosecond laser-induced Coulomb explosion. The structural determinations ... More
Van der Waals Interactions in DFT using Wannier Functions without empirical parametersFeb 19 2019A new implementation is proposed for including van der Waals (vdW) interactions in Density Functional Theory (DFT) using the Maximally-Localized Wannier functions (MLWFs), which is free from empirical parameters. With respect to the previous DFT/vdW-WF2 ... More
Graph Dynamical Networks: Unsupervised Learning of Atomic Scale Dynamics in MaterialsFeb 18 2019Understanding the dynamical processes that govern the performance of functional materials is essential for the design of next generation materials to tackle global energy and environmental challenges. Many of these processes involve the dynamics of individual ... More
A local perspective on conjugation of double bonds in acyclic polyenesFeb 18 2019The study is devoted to elaboration of an alternative image of conjugation in acyclic polyenes as a weak and essentially local delocalization of initially-localized pairs of electrons ascribed to individual double bonds (instead of formation of a completely ... More
New spectral characterization of dimethyl ether isotopologues CH$_3$OCH$_3$ and $^{13}$CH$_3$OCH$_3$ in the THz regionFeb 18 2019The torsional Raman spectra of two astrophysically detected isotopologues of dimethyl-ether, ($^{12}$CH$_3$O$^{12}$CH$_3$ and $^{13}$CH$_3$O$^{12}$CH$_3$), have been recorded at room temperature and cooled in supersonic jet, and interpreted with the help ... More
Unravelling the contribution of local structures to the anomalies of water: the synergistic action of several factorsFeb 17 2019We investigate the microscopic origin of water's anomalies by inspecting the hydrogen bond network (HBN) and the spatial organization of low-density-liquid (LDL) like and high-density-liquid (HDL) like environments. Specifically, we simulate --via classical ... More
Osmosis, from molecular insights to large-scale applicationsFeb 17 2019Osmosis is a universal phenomenon occurring in a broad variety of processes and fields. It is the archetype of entropic forces, both trivial in its fundamental expression - the van 't Hoff perfect gas law - and highly subtle in its physical roots. While ... More
Prediction of enthalpy for nitrogen gas revisedFeb 16 2019It is shown that the energy spectrum of the pure vibrational levels of the molecule consisting of two atoms interacting with each other via the modified Rosen-Morse potential, the analytical expressions for the vibrational partition function and enthalpy ... More
Cavity-enhanced high harmonic generation for XUV time-resolved ARPESFeb 15 2019With its direct correspondence to electronic structure, angle-resolved photoemission spectroscopy (ARPES) is a ubiquitous tool for the study of solids. When extended to the temporal domain, time-resolved (TR)-ARPES offers the potential to move beyond ... More
High Sensitivity Microwave Spectroscopy in a Cryogenic Buffer Gas CellFeb 15 2019We describe an instrument which can be used to analyze complex chemical mixtures at high resolution and high sensitivity. Molecules are collisionally cooled with helium gas at cryogenic temperatures (~ 4-7 K), and subsequently detected using chirped pulse ... More
Diagnosis of two evaluation paths to quantum-topological descriptors of molecular electronic transitionsFeb 15 2019In this paper we discuss the reliability of two computational methods (numerical integration on Cartesian grids, and population analysis) used for evaluating scalar quantities related to the nature of electronic transitions. These descriptors are integrals ... More
A Consistent Reduced Network for HCN Chemistry in Early Earth and Titan Atmospheres: Quantum Calculations of Reaction Rate CoefficientsFeb 14 2019HCN is a key ingredient for synthesizing biomolecules such as nucleobases and amino acids. We calculate 42 reaction rate coefficients directly involved with or in competition with the production of HCN in the early Earth or Titan atmospheres. These reactions ... More
New universal Lyapunov functions for non-linear reaction networksFeb 14 2019In 1961, R\'enyi discovered a rich family of non-classical Lyapunov functions for kinetics of the Markov chains, or, what is the same, for the linear kinetic equations. This family was parameterised by convex functions on the positive semi-axis. After ... More
Rate constants in spatially inhomogeneous systemsFeb 14 2019We present a theory and accompanying importance sampling method for computing rate constants in spatially inhomogenious systems. Using the relationship between rate constants and path space partition functions, we illustrate that the relative change in ... More
Atomistic machine learning between predictions and understandingFeb 13 2019The application of machine learning to the prediction of molecular and materials properties has become very fashionable in the last few years. In fact, machine-learning techniques have been used for a long time, called by more specific names such as clustering ... More
An extension of the fewest switches surface hopping algorithm to complex Hamiltonians and photophysics in magnetic fields: Berry's phase and "magnetic" forcesFeb 13 2019We present a preliminary extension of the fewest switches surface hopping (FSSH) algorithm to the case of complex Hamiltonians as appropriate for modeling the dynamics of photoexcited molecules in magnetic fields. We make ansatze for the direction of ... More
On Exact analytical calculations of thermodynamic functions of gaseous substances, R. Khordad, A. Avazpour, and A. Ghanbari, Chemical Physics 517 (2019) 30Feb 13 2019It is shown that that the exact solution of the Schrodinger equation for the molecule consisting of two atoms interacting via improved Tietz potential, the analytical expressions for the energy of the rotational-vibrational levels, partition function, ... More
Incorrectness of analytical solution of Schrodinger equation for diatomic molecule with shifted Tietz-Wei potentialFeb 13 2019It is shown that: the analytical solution of the stationary Schrodinger equation for diatomic molecules with the shifted Tietz-Wei potential, which was reported in the paper Exact and Poisson summation thermodynamic properties for diatomic molecules with ... More
Efficient Simulation of Near-Edge X-ray Absorption Fine Structure (NEXAFS) in Density-Functional Theory: Comparison of Core-Level Constraining ApproachesFeb 13 2019Widely employed Near-Edge X-Ray Absorption Fine Structure (NEXAFS) spectroscopy probes a system by excitation of core electrons to unoccupied states. A variety of different methodologies are available to simulate corresponding spectra from first-principles. ... More
Efficient geometric integrators for nonadiabatic quantum dynamics in the adiabatic basisFeb 12 2019The split-operator algorithm is popular for nonadiabatic quantum dynamics because it is explicit, easy to implement, and preserves many geometric invariants of the exact evolution; however, the algorithm can only be used in the diabatic basis, or, more ... More
Constraints on bosonic dark matter from ultralow-field nuclear magnetic resonanceFeb 12 2019The nature of dark matter, the invisible substance making up over $80\%$ of the matter in the Universe, is one of the most fundamental mysteries of modern physics. Ultralight bosons such as axions, axion-like particles or dark photons could make up most ... More
Removing instabilities in the hierarchical equations of motion: exact and approximate projection approachesFeb 12 2019The hierarchical equations of motion (HEOM) provide a numerically exact approach for computing the reduced dynamics of a quantum system linearly coupled to a bath. We have found that HEOM contains temperature-dependent instabilities that grow exponentially ... More