A5068883016- Advanced Chemical Physics Studies
- Spectroscopy and Quantum Chemical Studies
- Photochemistry and Electron Transfer Studies
- Spectroscopy and Laser Applications
- Atmospheric Ozone and Climate
- Mass Spectrometry Techniques and Applications
- Atmospheric chemistry and aerosols
- X-ray Spectroscopy and Fluorescence Analysis
- Machine Learning in Materials Science
- Atomic and Molecular Physics
- Computational Physics and Python Applications
- Physics of Superconductivity and Magnetism
- Molecular Junctions and Nanostructures
- Chalcogenide Semiconductor Thin Films
- NMR spectroscopy and applications
- Graphene research and applications
- Quantum Dots Synthesis And Properties
- Inorganic Fluorides and Related Compounds
- Molecular Spectroscopy and Structure
- Protein Structure and Dynamics
- Photoreceptor and optogenetics research
- Advanced Thermoelectric Materials and Devices
- Cold Atom Physics and Bose-Einstein Condensates
- Laser Design and Applications
- Laser-Matter Interactions and Applications
Technical University of Denmark
2019-2024
IMDEA Nanoscience
2023
Universidad Autónoma de Madrid
2023
Istituto Officina dei Materiali
2021
University of Trieste
2021
Universidade Federal do Rio de Janeiro
2016-2020
The developments of the open-source OpenMolcas chemistry software environment since spring 2020 are described, with a focus on novel functionalities accessible in stable branch package or via interfaces other packages. These span wide range topics computational and presented thematic sections: electronic structure theory, spectroscopy simulations, analytic gradients molecular optimizations, ab initio dynamics, new features. This report offers an overview chemical phenomena processes can...
The Dalton Project provides a uniform platform access to the underlying full-fledged quantum chemistry codes and LSDalton as well PyFraME package for automatized fragmentation parameterization of complex molecular environments. is written in Python defines means library communication interaction. Intermediate data such integrals are exposed made accessible user form NumPy arrays, resulting extracted, analyzed, visualized. Complex computational protocols that may, instance, arise due need...
Oxygen, nitrogen, and carbon K-shell photoabsorption photoionization cross sections have been calculated within core-valence-separated coupled cluster (CC) linear response theory for a number of molecular systems, namely, water, ammonia, ethylene, dioxide, acetaldehyde, furan, pyrrole. The below above the K-edge core ionization thresholds were obtained, on same footing, from L2 basis set calculations discrete electronic pseudospectrum yielded by an asymmetric-Lanczos-based formulation CC at...
Abstract A dynamical rearrangement in the electronic structure of a molecule can be driven by different phenomena, including nuclear motion, coherence or electron correlation. Recording such dynamics and identifying its fate an aqueous solution has remained challenge. Here, we reveal induced relaxation through conical intersections both isolated solvated pyrazine molecules using X-ray spectroscopy. We show that ensuing created corresponds to cyclic around aromatic ring. Furthermore, found...
A methodology to calculate the decay rates of normal and resonant Auger processes in atoms molecules based on One-Center Approximation (OCA), using atomic radial integrals, is implemented within restricted-active-space self-consistent-field (RASSCF) multistate perturbation theory second order (MS-RASPT2) frameworks, as part OpenMolcas project. To ensure an unbiased description correlation relaxation effects initial core excited/ionized states final cationic states, their wave functions are...
We present a theoretical model to compute the accurate photoionization dynamical parameters (cross-sections, asymmetry and orbital, or cross-section, ratios) from Dyson orbitals obtained with multi-state complete active space perturbation theory second order (MS-CASPT2) method. Our new implementation of in OpenMolcas takes advantage full Abelian symmetry point group has corrected normalization. The are coupled an description electronic continuum multicentric B-spline basis at DFT TD-DFT...
To simulate photoionization and photodetachment cross sections, as well polarizability dispersion profiles below the ionization threshold, a discretized (pseudo)spectrum stretching over entire frequency region (including continuum) obtained from an asymmetric Lanczos algorithm at coupled cluster singles doubles level is used to reconstruct complex dipole polarizability, on which analytic continuation procedure then applied. Through suitable selection of points in plane, we have shown can be...
Autoionization spectra of CH2Cl2 and CD2Cl2 molecules after Cl 2p excitation are studied. The two molecular atomic Auger transitions examined assigned. contribution is lower in the deuterated molecule. In addition, to support presence ultrafast dissociation mechanism dichloromethane molecule, a series high-level ab initio quantum mechanical calculations were performed at multiconfigurational self-consistent field (MCSCF) multireference configuration interaction (MRCI) levels theory. Minimum...
We investigate the resonant and non-resonant Auger spectra of ozone with a newly implemented multi-reference protocol based on one-center approximation [Tenorio et al., J. Chem. Theory Comput. 2022, 18, 4387-4407]. The results our calculations are compared to existing experimental data, where we elucidate spectrum measured at 530.8 536.7 eV, that correspond 1sOT → π*(2b1) σ*(7a1) resonances, 542.3 which lies near 1sOC excited state above 1sOT-1 ionization threshold. Using molecular dynamics...
We have measured, analyzed, and simulated the ground state valence photoelectron spectrum, x-ray absorption (XA) (XP) spectrum as well normal resonant Auger-Meitner electron (AE) of oxazole at carbon, oxygen, nitrogen K-edge in order to understand its electronic structure. Experimental data are compared theoretical calculations performed coupled cluster, restricted active space perturbation theory second-order time-dependent density functional levels theory. demonstrate (1) that both N O XA...
The time-dependent version of the density functional theory (TDDFT) has been used to calculate total photoabsorption cross section a number molecules, namely, benzene, pyridine, furan, pyrrole, thiophene, phenol, naphthalene, and anthracene. discrete electronic pseudo-spectra, obtained in L2 basis set calculation were an analytic continuation procedure obtain sections. ammonia molecule was chosen as model system compare results with TDDFT those linear response coupled cluster approach order...
Excitation energies and oscillator strengths of the first two electronically excited states helium, water, sulfur dioxide, molecular nitrogen, carbon monoxide were obtained from an asymmetric-Lanczos-based formulation equation-of-motion coupled cluster singles doubles approach. The total photoionization cross sections generated by different methodologies: analytic continuation procedure based on Padé approximants Stieltjes imaging technique. results are compared with theoretical algebraic...
Double Core-Hole (DCH) states of small molecules are assessed with the restricted active space self-consistent field and multi-state perturbation theory second order approximations. To ensure an unbiased description relaxation correlation effects on DCH states, neutral ground-state wave functions optimized separately, whereas spectral intensities computed a biorthonormalized set molecular orbitals within state-interaction approximation. Accurate shake-up satellite binding energies...
Near K-edge photoabsorption cross section spectra of a number molecules, namely, water, ammonia, acetone, acetaldehyde, furan, and pyrrole, were obtained at the nitrogen, oxygen, carbon K-edges with Coupled Cluster ansatz (CC) Time-Dependent Density Functional Theory (TDDFT) by treating inner shell excitations as individual channels, separated from valence part spectrum. The discretized electronic pseudospectrum, quadratically integrable basis sets ( a.k.a. L2) CC or TDDFT level, is used to...
We present a theoretical investigation of the near-edge X-ray absorption fine structure and Auger–Meitner decay spectra ethylene its cation. Herein, we demonstrate that our method, coupled with nuclear ensemble approach, successfully reproduces natural bandwidth experimental resonant ethylene, which is not very well reproduced within Franck–Condon approximation. Furthermore, analyze cation in light minimum energy conical intersection structures involving two lowest cationic states (D1 D0),...
The photofragmentation dynamics of 1,1,1,2-tetrafluoroethane (R134a) with photon energies from 12 eV up to 320 eV, surrounding the C 1s edge is discussed. ionic moieties were measured in coincidence ejected electrons (PEPICO mode), and detected as a function energy. Around K core edge, fragmentation profiles are examined regarding site specific excitation CH2FCF3 molecule. In present case, site-selectivity favored by distinct chemical environments both atoms. NEXAFS spectrum at simulation...
We report on single- and double-charge photofragment formation by synchrotron radiation, following C 1s core excitation ionization Cl 2p inner of chlorobenzene, C6H5Cl. From a comparison experimental near-edge X-ray absorption fine structure spectra theoretical ab initio calculations, the nature various shell transitions molecule pure atomic features were identified. To shed light normal Auger processes or at sites, we addressed induced ionic species formation. With energy resolved electron...
Inner-shell absolute photoabsorption and photoionization cross sections of the formic acid, HCOOH, its small hydrogen-bonded clusters, i.e., (HCOOH)2, HCOOH2+, HCOHOH+, HCOOH·H3O+, were calculated at time-dependent density functional theory (TDDFT) level, results used to analyze effect acid clustering on carbon oxygen K-edge sections. The discrete electronic pseudospectra obtained with square-integrable (L2) basis set calculations in an analytic continuation procedure based continued...
A theoretical study of the K-shell total photoabsorption and photoionization cross section spectra water ammonia bonded to benzene (C6H6) polycyclic aromatic hydrocarbons (PAHs) naphthalene (C10H8), coronene (C24H12) circumcoronene (C54H18) by van der Waals (vdW) forces is presented. The discretized electronic pseudospectra at oxygen nitrogen K-edges, covering discrete continuum spectral regions, were obtained time-dependent density functional theory (TDDFT) level with dispersion correction....
(2021). Inner-shell photoabsorption and photoionisation cross-sections of valence excited states from asymmetric-Lanczos equation-of-motion coupled cluster singles doubles theory. Molecular Physics: Vol. 119, Special Issue Physics in Honour John Stanton, e1980235.
An experimental and theoretical study of the photoinduced homolysis carbon-chlorine bond in an ice matrix chlorobenzene is presented. A condensed film has been grown situ near edge X-ray fine structure (NEXAFS) spectra were collected after exposing to a monochromatic photon beam centered at 2822 eV resonant excitation chlorine 2850 eV. The photoabsorption Cl 1s → σ* π* states measured hypothesis free radical coupling reactions was investigated via time-dependent density functional theory...