Browsing Chemistry & Biochemistry by Issue Date

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Sequential addition of H2O, CH3OH, and NH3 to Al3O3-: A theoretical study

Guevara-Garcia, Alfredo; Martinez, Ana; Ortiz, J.V. (2021-01-26)

Photoelectron spectra of two species, Al3O3(H2O)(2)(-) and Al3O3(CH3OH)(2)(-), that are produced by the addition of two water or methanol molecules to Al3O3- are interpreted with density-functional geometry optimizations ...

Platinum, gold, and silver standards of intermolecular interaction energy calculations

Kodrycka, Monika; Patkowski, Konrad; https://orcid.org/0000-0002-4468-207X (2020-03-10)

High-accuracy noncovalent interaction energies are indispensable as data points for potential energy surfaces and as benchmark values for improving and testing more approximate approaches. The preferred algorithm (the gold ...

Direct ΔMBPT(2) method for ionization potentials, electron affinities, and excitation energies using fractional occupation numbers

Beste, Ariana; Vazquez-Mayagoitia, Alvaro; Ortiz, J. V.; Ortiz, Joseph V. (2020-01-16)

A direct method (D-ΔMBPT(2)) to calculate second-order ionization potentials (IPs), electron affinities (EAs), and excitation energies is developed. The ΔMBPT(2) method is defined as the correlated extension of the ΔHF ...

Assignment of photoelectron spectra of halide–water clusters: Contrasting patterns of delocalization in Dyson orbitals

Dolgounitcheva, O.; Zakrzewski, V. G.; Ortiz, J. V.; Ortiz, Joseph V. (2020-01-16)

Ab initio electron propagator calculations in various self-energy approximations provide accurate assignments of peaks observed in the photoelectron spectra of complexes that comprise a fluoride or chloride anion and two ...

Cluster perturbation theory. II. Excitation energies for a coupled cluster target state

Pawlowski, Filip; Olsen, Jeppe; Jorgensen, Poul; 0000-0002-5928-2140 (2020-05-07)

In cluster perturbation (CP) theory, we consider a target excitation space relative to a Hartree-Fock state and partition the target excitation space into a parent excitation space and an auxiliary excitation space. The ...

Spin splittings from first-order symmetry-adapted perturbation theory without single-exchange approximation

Waldrop, Jonathan; Patkowski, Konrad; 0000-0003-0442-193X; 0000-0002-4468-207X (2020-05-20)

The recently proposed spin-flip symmetry-adapted perturbation theory (SF-SAPT) first-order exchange energy [Patkowski et al., J. Chem. Phys. 148, 164110 (2018)] enables the standard open-shell SAPT approach to treat arbitrary ...

Second-order, two-electron Dyson propagator theory: Comparisons for vertical double ionization potentials

Ida, T.; Ortiz, J.V. (2021-01-26)

The second-order, two-electron Dyson propagator is derived using superoperator theory with a spin-adapted formulation. To include certain ladder diagrams to all orders, the shifted-denominator SD2 approximation is made. ...

First-order symmetry-adapted perturbation theory for multiplet splittings

Patkowski, Konrad; Zuchowski, Piotr S.; Smith, Daniel G. A.; https://orcid.org/0000-0002-4468-207X (2020-06-25)

We present a symmetry-adapted perturbation theory (SAPT) for the interaction of two high-spin open-shell molecules (described by their restricted open-shell Hartree-Fock determinants) resulting in low-spin states of the ...

Cluster perturbation theory. IV. Convergence of cluster perturbation series for energies and molecular properties

Pawlowski, Filip; Olsen, Jeppe; Jorgensen, Poul; 0000-0002-5928-2140 (2020-05-20)

The theoretical foundation has been developed for establishing whether cluster perturbation (CP) series for the energy, molecular properties, and excitation energies are convergent or divergent and for using a two-state ...

Quasiparticle virtual orbitals in electron propagator calculations

Flores-Moreno, Roberto; Ortiz, J.V. (2021-01-26)

The computational limits of accurate electron propagator methods for the calculation of electron binding energies of large molecules are usually determined by the rank of the virtual orbital space. Electron density ...

Partial photoionization cross sections of and Rydberg radicals

Velasco, A.M.; Lavin, C.; Martin, I.; Melin, J.; Ortiz, J.V. (2021-01-26)

ammonium and oxonium Rydberg radicals from the outermost, occupied orbitals of their respective ground states are reported. These properties are known to be relevant in photoelectron dynamics studies. For the present ...

Basis set converged weak interaction energies from conventional and explicitly correlated coupled-cluster approach

Patkowski, Konrad (2020-01-16)

Interaction energies for seven weakly bound dimers involving helium, argon, water, and methane are computed using large correlation-consistent basis sets augmented with bond functions. The estimates of the coupled-cluster ...

A generalized any-particle propagator theory: Prediction of proton affinities and acidity properties with the proton propagator

Diaz-Tinoco, Manuel; Romero, Jonathan; Ortiz, J. V.; Reyes, Andres; Flores-Moreno, Roberto; Ortiz, Joseph V. (2020-01-16)

We have recently extended the electron propagator theory to the treatment of any type of particle using an Any-Particle Molecular Orbital (APMO) wavefunction as reference state. This approach, called APMO/PT, has been ...

Interpretation of the photoelectron spectra of superalkali species: Li3O and Li3O-

Zein, S.; Ortiz, J. V. (2020-10-02)

The present paper deals with the interpretation of the photoelectron spectrum of the Li3O-. After several failed attempts to attribute all of the observed peaks in the experimental spectrum to anionic species, neutral ...

Eukaryotic N-Glycosylation Occurs via the Membrane-anchored C-terminal Domain of the Stt3p Subunit of Oligosaccharyltransferase

Huang, Chengdong; Bhaskaran, Rajagopalan; Mohanty, Smita (2020-07-24)

N-Glycosylation is an essential and highly conserved protein modification. In eukaryotes, it is catalyzed by a multisubunit membrane-associated enzyme, oligosaccharyltransferase (OT). We report the high resolution ...