A5066714385- Spectroscopy and Quantum Chemical Studies
- Advanced Chemical Physics Studies
- Quantum, superfluid, helium dynamics
- Photochemistry and Electron Transfer Studies
- Quantum Computing Algorithms and Architecture
- Neuropeptides and Animal Physiology
- Trace Elements in Health
- Molecular Junctions and Nanostructures
- Quantum and electron transport phenomena
- Electron Spin Resonance Studies
- Regulation of Appetite and Obesity
- Parallel Computing and Optimization Techniques
- Advanced Physical and Chemical Molecular Interactions
- Heavy Metal Exposure and Toxicity
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum many-body systems
- Photosynthetic Processes and Mechanisms
- Stress Responses and Cortisol
- Molecular spectroscopy and chirality
- Magneto-Optical Properties and Applications
- Aluminum toxicity and tolerance in plants and animals
- Hypothalamic control of reproductive hormones
- Electromagnetic Simulation and Numerical Methods
- TiO2 Photocatalysis and Solar Cells
- Perovskite Materials and Applications
University of California, Berkeley
2013-2024
Ames Research Center
2020-2022
KBR (United States)
2021-2022
University of California, Santa Barbara
2021
Lawrence Berkeley National Laboratory
2013-2019
University of California System
2016
NOAA Chemical Sciences Laboratory
2016
Berkeley College
2016
Center for Theoretical Biological Physics
2016
California State University, Fullerton
1998-2000
A microscopically reversible approach toward computing reaction probabilities via classical trajectory simulation has been developed that bins trajectories symmetrically on the basis of their initial and final actions. The symmetrical quasi-classical (SQC) involves defining a action window function centered at integer quantum values action, choosing width parameter is less than unit width, applying to both reactant product vibrational states. Calculations were performed using flat histogram...
A recently described symmetrical windowing methodology [S. J. Cotton and W. H. Miller, Phys. Chem. 117, 7190 (2013)] for quasi-classical trajectory simulations is applied here to the Meyer-Miller [H.-D. Meyer 70, 3214 (1979)] model electronic degrees of freedom in electronically non-adiabatic dynamics. Results generated using this classical approach are observed be very good agreement with accurate quantum mechanical results a variety test applications, including problems where coherence...
Both classical and quantum mechanics (as well as hybrids thereof, <italic>i.e.</italic>, semiclassical approaches) find widespread use in simulating dynamical processes molecular systems. For large chemical systems, however, which involve potential energy surfaces (PES) of general/arbitrary form, it is usually the case that only dynamics (MD) approaches are feasible, their thus ubiquitous nowadays, at least for involving on a single PES (<italic>i.e.</italic>, within Born–Oppenheimer...
In a recent series of papers, it has been illustrated that symmetrical quasi-classical (SQC) windowing model applied to the Meyer-Miller (MM) classical vibronic Hamiltonian provides an excellent description variety electronically non-adiabatic benchmark systems for which exact quantum results are available comparison. this paper, SQC/MM approach is used treat energy transfer dynamics in site-exciton models light-harvesting complexes, and particular, well-known 7-state Fenna-Mathews-Olson...
Strongly correlated quantum systems give rise to many exotic physical phenomena, including high-temperature superconductivity. Simulating these on computers may avoid the prohibitively high computational cost incurred in classical approaches. However, systematic errors and decoherence effects presented current devices make it difficult achieve this. Here, we simulate dynamics of one-dimensional Fermi-Hubbard model using 16 qubits a digital superconducting processor. We observe separations...
In this work we present a detailed analysis of variational quantum phase estimation (VQPE), method based on real-time evolution for ground- and excited-state near-term hardware. We derive the theoretical ground which approach stands, demonstrate that it provides one most compact expansions to date solving strongly correlated Hamiltonians, when starting from an appropriate reference state. At center VQPE lies set equations, with simple geometrical interpretation, conditions time grid in order...
It has recently been shown [S. J. Cotton and W. H. Miller, Chem. Phys. 139, 234112 (2013)] that a symmetrical windowing quasi-classical (SQC) approach A 117, 7190 applied to the Meyer-Miller model [H.-D. Meyer 70, 3214 (1979)] for electronic degrees of freedom in electronically non-adiabatic dynamics is capable quantitatively reproducing quantum mechanical results variety test applications, including cases where “quantum” coherence effects are significant. Here we apply this same SQC...
The Meyer-Miller (MM) classical vibronic (electronic + nuclear) Hamiltonian for electronically non-adiabatic dynamics-as used, example, with the recently developed symmetrical quasiclassical (SQC) windowing model-can be written in either a diabatic or an adiabatic representation of electronic degrees freedom, two being canonical transformation each other, thus giving same dynamics. Although most recent applications this SQC/MM approach have been carried out representation-because benchmark...
Previous work has shown how a symmetrical quasi-classical (SQC) windowing procedure can be used to quantize the initial and final electronic degrees of freedom in Meyer-Miller (MM) classical vibronic (i.e, nuclear + electronic) Hamiltonian, that approach provides very good description electronically non-adiabatic processes within standard molecular dynamics framework for number benchmark problems. This paper explores application SQC/MM case weak coupling between states, showing (as...
In the previous work of Cotton and Miller [J. Chem. Phys. 145, 144108 (2016)], an improved symmetrical quasi-classical (SQC) windowing model for molecular dynamics treatment electronically non-adiabatic processes was developed in order to extend original SQC approach regime weak-coupling between electronic states. The model-based on triangular-shaped window functions-handled limit as intended and, a bonus, shown be universally superior square/histogram over all coupling regimes, but only...
An electronic zero-point energy (ZPE) adjustment protocol is presented within the context of symmetrical quasiclassical (SQC) quantization oscillator degrees freedom (DOF) in classical Meyer-Miller (MM) vibronic dynamics for molecular treatment electronically nonadiabatic processes. The "adjustment" procedure maintains same initial and final distributions coordinates momenta DOF as previously given by SQC windowing but modifies ZPE parameter MM Hamiltonian, on a per trajectory basis, so that...
Neuropeptide Y (NPY) concentrations were measured by radioimmunoassay in eight microdissected hypothalamic regions of obese (fa/fa) and lean (Fa/?) Zucker rats. Freely fed rats showed significant (40–100%) increases NPY several regions, notably the paraventricular, ventromedial, dorsomedial nuclei arcuate nucleus/median eminence, compared with Hypothalamic not affected either or food restriction, which caused 25% weight loss over 3 wk. Refeeding to initial significantly increased levels...
A recent series of papers has shown that a symmetrical quasi-classical (SQC) windowing procedure applied to the Meyer-Miller (MM) classical vibronic Hamiltonian provides very good treatment electronically nonadiabatic processes in variety benchmark model systems, including systems exhibit strong quantum coherence effects and some which other approximate approaches have difficulty describing correctly. In this paper, different electronic for is proposed (and "quantized" via SQC approach),...
It is noted that the recently developed symmetrical quasi-classical (SQC) treatment of Meyer-Miller (MM) model for simulation electronically non-adiabatic dynamics provides a good description detailed balance, even though which results from classical MM Hamiltonian "Ehrenfest dynamics" (i.e., force on nuclei an instantaneous coherent average over all electronic states). This seen to be consequence SQC windowing methodology "processing" trajectory calculation. For particularly simple...
It is pointed out that the classical phase space distribution in action-angle (a-a) variables obtained from a Wigner function depends on how calculation carried out: if one computes standard Cartesian (p, x), and then replaces p x by their expressions terms of a-a variables, obtains different result than computed directly variables. Furthermore, latter procedure gives more consistent with semiclassical theory—e.g., incorporating Bohr-Sommerfeld quantization condition (quantum states defined...
Photo-emission spectroscopy directly probes individual electronic states, ranging from single excitations to high-energy satellites, which simultaneously represent multiple quasiparticles (QPs) and encode information about correlation. The first-principles description of the spectra requires an efficient accurate treatment all many-body effects. This is especially challenging for inner valence where QP picture breaks down. Here, we provide full small closed-shell molecules, exploring...
In the last several years, a symmetrical quasi-classical (SQC) windowing model applied to classical Meyer-Miller (MM) vibronic Hamiltonian has been shown be simple, efficient, general, and quite-accurate method for treating electronically nonadiabatic processes at totally level. Here, SQC/MM methodology is ultrafast exciton dynamics in Frenkel/site-exciton of oligothiophene (OT) as organic semiconductor polymers. order keep electronic representation compact efficient possible, adiabatic...
Objective— To control insulin-induced edema in a patient with poorly controlled IDDM. Research Design and Methods— A 31-yr-old woman 14-yr history of IDDM first developed peripheral 3 yr after diagnosis IDDM; the worsened whenever insulin dosage was increased. In August 1991, severe treatment ketoacidosis, body weight increasing from 46 to 61 kg. No evidence cardiac dysfunction or autonomic neuropathy existed, serum albumin consistently normal. Results— Treatment 15 mg ephedrine every 8 h...
Quantum computation promises to provide substantial speedups in many practical applications with a particularly exciting one being the simulation of quantum many-body systems. Adiabatic state preparation (ASP) is way that computers could recreate and simulate ground physical system. In this paper, we explore novel approach for classically simulating time dynamics ASP high accuracy only modest computational resources via an adaptive sampling configuration interaction scheme truncating Hilbert...
The successful use of molecular dyes for solar energy conversion requires efficient charge injection, which in turn the formation states with sufficiently long lifetimes (e.g., triplets). structure elements that confer this property can be found empirically, however computational predictions using ab initio electronic methods are invaluable to identify structure-property relations dye sensitizers. primary challenge simulations elucidate and nuclear origins these properties is a spin-orbit...