SCINE—Software for chemical interaction networks

The Journal of Chemical Physics, Год журнала: 2024, Номер 160(22)

Опубликована: Июнь 10, 2024

The software for chemical interaction networks (SCINE) project aims at pushing the frontier of quantum calculations on molecular structures to a new level. While individual as well simple relations between them have become routine in chemistry, developments pushed field high-throughput calculations. Chemical may be created by search specific properties design attempt, or they can defined set elementary reaction steps that form network. modules SCINE been designed facilitate such studies. features are (i) general applicability applied methodologies ranging from electronic structure (no restriction elements periodic table) microkinetic modeling (with little restrictions molecularity), full modularity so also stand-alone programs exchanged external packages fulfill similar purpose (to increase options computational campaigns and provide alternatives case tasks hard impossible accomplish with certain programs), (ii) high stability autonomous operations control steering an operator easy possible, (iii) embedding into complex heterogeneous environments taken individually context A graphical user interface unites all ensures interoperability. All components made available open source free charge.

Язык: Английский

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Forte: A suite of advanced multireference quantum chemistry methods

The Journal of Chemical Physics, Год журнала: 2024, Номер 161(6)

Опубликована: Авг. 12, 2024

Forte is an open-source library specialized in multireference electronic structure theories for molecular systems and the rapid prototyping of new methods. This paper gives overview capabilities Forte, its software architecture, examples applications enabled by methods it implements.

Язык: Английский

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Renormalized-Residue-Based Multireference Configuration Interaction Method for Strongly Correlated Systems

Journal of Chemical Theory and Computation, Год журнала: 2024, Номер 20(5), С. 1988 - 2009

Опубликована: Фев. 21, 2024

The implementation of multireference configuration interaction (MRCI) methods in quantum systems with large active spaces is hindered by the expansion bases or intricate handling reduced density matrices (RDMs). In this work, we present a spin-adapted renormalized-residue-based MRCI (RR-MRCI) approach that leverages renormalized residues to effectively capture entanglement between and inactive orbitals. This reinforced novel efficient algorithm, which also facilitates an deployment matrix product state (MPS-MRCI). RR-MRCI framework possesses several advantages: (1) It considers orbital utilizes highly compressed MPS structure, improving computational accuracy efficiency compared internally contracted (ic) MRCI. (2) Utilizing small-sized buffer environments few external orbitals as probes based on information theory, it enhances over MPS-MRCI offers potential application molecular systems. (3) RR can be implemented conjunction ic-MRCI, eliminating need for high-rank RDMs, using distinct residues. We evaluated method across nine diverse systems, including Cu

Язык: Английский

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Using a multistate mapping approach to surface hopping to predict the ultrafast electron diffraction signal of gas-phase cyclobutanone

The Journal of Chemical Physics, Год журнала: 2024, Номер 160(20)

Опубликована: Май 28, 2024

Using the recently developed multistate mapping approach to surface hopping (multistate MASH) method combined with SA(3)-CASSCF(12,12)/aug-cc-pVDZ electronic structure calculations, gas-phase isotropic ultrafast electron diffraction (UED) of cyclobutanone is predicted and analyzed. After excitation into n-3s Rydberg state (S2), can relax through two S2/S1 conical intersections, one characterized by compression CO bond other dissociation α-CC bond. Subsequent transfer ground (S0) then achieved via additional S1/S0 intersections that lead three reaction pathways: α ring-opening, ethene/ketene production, liberation. The UED signal from MASH simulations, allowing for a direct comparison experimental data. This work, which contribution prediction challenge, facilitates identification main photoproducts in thereby emphasizes importance dynamics simulations interpretation experiments.

Язык: Английский

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Near-infrared luminescent open-shell π-conjugated systems with a bright lowest-energy zwitterionic singlet excited state

Science Advances, Год журнала: 2024, Номер 10(30)

Опубликована: Июль 24, 2024

Open-shell systems with extensive π-conjugation have fascinating properties due to their narrow bandgaps and spin interactions. In this work, we report neutral open-shell di- polyradical conjugated materials exhibiting intriguing optical magnetic properties. Our key design advance is the planarized geometry allowing for greater interaction between adjacent spins. This results in absorption emission near infrared at 803 1050 nanometers, respectively, demonstrate a unique electronic structure where bright zwitterionic excited state lowest-accessible transition. Electron paramagnetic resonance spectroscopy superconducting quantum interference device measurements reveal that our are singlets different degrees of interactions, dynamics, antiferromagnetic properties, which likely contributed formation emissive singlet near-infrared emission. addition, show reversible stable electrochromic switching more than 500 cycles, indicating potential optoelectronic electrochemical energy storage applications.

Язык: Английский

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A Cost‐Effective Computational Strategy for the Electronic Layout Characterization of a Second Generation Light‐Driven Molecular Rotary Motor in Solution

Journal of Computational Chemistry, Год журнала: 2025, Номер 46(2)

Опубликована: Янв. 11, 2025

ABSTRACT Light‐driven molecular rotary motors are nanometric machines able to convert light into unidirectional motions. Several types of have been developed better respond stimuli, opening new avenues for developing smart materials ranging from nanomedicine robotics. They great importance in the scientific research across various disciplines, but a detailed comprehension underlying ultrafast photophysics immediately after photo‐excitation, that is, Franck–Condon region characterization, is not fully achieved yet. For this aim, it first required rely on an accurate description at ab initio level system potential energy before performing any further step, dynamics. Thus, we present extensive investigation aimed accurately describing electronic structure low‐lying states (electronic layout) rotor region, belonging class overcrowded alkenes: 9‐(2‐methyl‐2,3‐dihydro‐1H‐cyclopenta[a]naphthalen‐1‐ylidene)‐9H‐fluorene. This was chosen since its very interesting more general understanding similar compounds used as rotors, where can be found (whose energetic interplay crucial dynamics) and presence different substituents tune HOMO‐LUMO gap. scope, employed theory levels within time‐dependent density functional framework, presenting also careful comparison adopting post Hartree–Fock methods characterizing conformations involved photocycle. Effects layout functionals, basis sets, environment descriptions, role dispersion correction were all analyzed detail. In particular, treatment solvent effects here considered depth, showing how implicit excited by testing both linear‐response state‐specific formalisms. As main results, chose two cost‐effective (accurate relatively cheap) ground state verified choosing these influence curvature via frequency analysis normal modes vibrations active Raman spectrum. theoretical survey step towards feasible characterization early stage solution during photoisomerization processes wherein multiple might populated upon radiation, leading future molecular‐level interpretation time‐resolved spectroscopies.

Язык: Английский

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DNA Triplet Energies by Free Energy Perturbation Theory

Journal of Chemical Theory and Computation, Год журнала: 2025, Номер unknown

Опубликована: Янв. 24, 2025

Determining the energetics of triplet electronic states nucleobases in biological macromolecular environment nucleic acids is essential for an accurate description mechanism photosensitization and design drugs cancer treatment. In this work, we aim at developing a methodological approach to obtain free energies triplets DNA beyond state art, able reproduce decrease measured experimentally T (270 kJ/mol) vs isolated nucleotide aqueous solution (310 kJ/mol). For such purposes, adapt energy perturbation method compute related transformation pure singlet into via "alchemical" intermediates with mixed singlet–triplet nature. By means, standard deviation errors are only few kJ/mol, contrary large tenths kJ/mol obtained by averaging derived from molecular dynamics simulations. The reduced statistical allow us rationalize confidence stabilization observed when comparing thymine DNA. Spin polarization rather than excimer interactions between π-stacked originates lower values developed implemented QM3 shall be useful determining other like ionic or charge separation any system impact biomedicine materials science.

Язык: Английский

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Spin–Orbit Coupling and Admixture Coefficients in SA-CASSCF and MS-CASPT2, and Triplet Excitation Yield Simulated via Trajectory Surface Hopping and Calibrated SA-CASSCF in 1,2-Dioxetane Derivatives

The Journal of Physical Chemistry A, Год журнала: 2025, Номер unknown

Опубликована: Янв. 26, 2025

The energy gaps, spin-orbit coupling (SOC), and admixture coefficients over a series of the configurations are evaluated by SA-CASSCF/6-31G, SA-CASSCF/6-31G*, SA-CASSCF/ANO-RCC-VDZP, MS-CASPT2/ANO-RCC-VDZP to reveal extent inaccuracy SA-CASSCF. By comparing mean absolute errors for gaps coefficient magnitudes (ACMs) measured between or SA-CASSCF/ANO-RCC-VDZP MS-CASPT2/ANO-RCC-VDZP, SA-CASSCF/6-31G is selected as electronic structure method in nonadiabatic molecular dynamics simulation. major components ACMs identified compared; we find that underestimated which verified reasonable triplet quantum yield simulated trajectory surface hopping calibrated SA-CASSCF/6-31G. magnitude singlet-triplet mixing positively correlates probability mixed singlet states, confirmed computed S-T transition probability.

Язык: Английский

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Exciton Delocalization and Triplet Diffusion in Singlet Fission Materials: A Many-Electron Tight-Binding and Non-Orthogonal CI Study

The Journal of Physical Chemistry C, Год журнала: 2025, Номер unknown

Опубликована: Янв. 28, 2025

Язык: Английский

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³¹P NMR Chemical Shift Anisotropy in Paramagnetic Lanthanide Phosphide Complexes

JACS Au, Год журнала: 2025, Номер 5(3), С. 1196 - 1212

Опубликована: Фев. 21, 2025

Lanthanide (Ln) magnetic resonance imaging and chiral shift reagents generally exploit 1H NMR shifts, as paramagnetic broadening tends to preclude the use of heavier, less sensitive nuclei. Here, we report solution solid-state 31P shifts an isostructural series distorted trigonal bipyramidal Ln(III) tris-silylphosphide complexes, [Ln{P(SiMe3)2}3(THF)2] (1-Ln; Ln = La, Ce, Pr, Nd, Sm); 1-Ln was also characterized by elemental analysis; single-crystal powder X-ray diffraction; multinuclear NMR, EPR, ATR-IR, UV–vis-NIR spectroscopy; SQUID magnetometry. Breaking assumptions, observed paramagnetically broadened spectra for Ln-bound P atoms family; in solution, 1-Nd showed most downfield chemical (δ{31P} 2570.14 ppm) 1-Sm upfield value −259.21 ppm). We determined span anisotropies (CSAs) solid using magic angle spinning CSA largest 1-Pr (Ω{31P} ≈ 2000 ppm), consistent with a combination paramagnetism relatively large differences pyramidalization three solid-state. Density functional theory calculations 1-La were excellent agreement experimentally parameters. find good experimental ab initio-calculated values 1-Ln, while heavier 13C, 29Si, nuclei are not well-reproduced due current limitations contact shifts.

Язык: Английский

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