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At least 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Ab initio investigations of the electronic structure and chemical bonding of Li{sub 2}ZrN{sub 2}

The electronic structure of the ternary nitride Li{sub 2}ZrN{sub 2} is examined from ab initio with DFT computations for an assessment of the properties of chemical bonding. The compound is found insulating with 1.8 eV band gap; it becomes metallic and less ionic upon removal of one equivalent of Li. The chemical interaction is found mainly between Zr and N on one hand and Li and N on the other hand. While all pair interactions are bonding, antibonding N-N interactions are found dominant at the top of the valence band of Li{sub 2}ZrN{sub 2} and they become less intense upon removal of Li. From energy differences the partial delithiation leading to Li{sub 2-x}ZrN{sub 2} (x={approx}1) is favored. - Graphical abstract: Trigonal structure of Li{sub 2}ZrN{sub 2} showing the Zr-N-Li layers along the c-axis. Highlights: Black-Right-Pointing-Pointer Li{sub 2}ZrN{sub 2} calculated insulating with a 1.8 eV gap in agreement with its light green color. Black-Right-Pointing-Pointer Lithium de-intercalation is energetically favored for one out of two Li equivalents. Black-Right-Pointing-Pointer Li plays little role in the change of the structure, ensured by Zr and N binding. Black-Right-Pointing-Pointer Similar changes in the electronic structure as for various intercalated phases of ZrN.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Electronic structure modulation of MoS2 by substitutional Se incorporation and interfacial MoO3 hybridization: Implications of Fermi engineering for electrocatalytic hydrogen evolution and oxygen evolution

The design of earth-abundant electrocatalysts that can facilitate water splitting at low overpotentials, provide high current densities, and enable prolonged operational lifetimes is central to the production of sustainable fuels. The distinctive atomistic and electronic structure characteristics of the edges of MoS2 imbue high reactivity toward the hydrogen evolution reaction. MoS2 is nevertheless characterized by significantly high overpotentials as compared to platinum. Here, we demonstrate that modulation of the electronic structure of MoS2 through interfacial hybridization with MoO3 and alloying of selenium on the anion sublattice allows for systematic lowering of the conduction band edge and raising of the valence band edge, respectively. The former promotes enhanced electrocatalytic activity toward hydrogen evolution, whereas the latter promotes enhanced activity toward the oxygen evolution reaction. Such alloyed heterostructures prepared by sol-gel reactions and hydrothermal selenization expose a high density of edge sites. The alloyed heterostructures exhibit low overpotential, high current density, high turnover frequency, and prolonged operational lifetime. The mechanistic origins of catalytic activity have been established based on electronic structure calculations and x-ray absorption and emission spectroscopy probes of electronic structure, which suggest that interfacial hybridization at the MoO3 interface yields low-lying conduction band states that facilitate hydrogen adsorption. In contrast, shallow Se 4p-derived states give rise to a raised effective valence band maximum, which facilitates adsorption of oxygen intermediates and engenders a low overpotential for the oxygen evolution reaction. The findings illustrate the use of electronic structure modulation through interfacial hybridization and alloying to systematically improve electrocatalytic activity.

Parija, Abhishek↗
DOE OSTI2017

Electronic structure of R Sb ( R = Y , Ce, Gd, Dy, Ho, Tm, Lu) studied by angle-resolved photoemission spectroscopy

Here, we use high-resolution angle-resolved photoemission spectroscopy (ARPES) and electronic structure calculations to study the electronic properties of rare-earth monoantimonides RSb (R = Y, Ce, Gd, Dy, Ho, Tm, Lu). The experimentally measured Fermi surface (FS) of RSb consists of at least two concentric hole pockets at the Γ point and two intersecting electron pockets at the X point. These data agree relatively well with the electronic structure calculations. Detailed photon energy dependence measurements using both synchrotron and laser ARPES systems indicate that there is at least one Fermi surface sheet with strong three-dimensionality centered at the Γ point. Due to the “lanthanide contraction”, the unit cell of different rare-earth monoantimonides shrinks when changing the rare-earth ion from CeSb to LuSb. This results in the differences in the chemical potentials in these compounds, which are demonstrated by both ARPES measurements and electronic structure calculations. Interestingly, in CeSb, the intersecting electron pockets at the X point seem to be touching the valence bands, forming a fourfold-degenerate Dirac-like feature. On the other hand, the remaining rare-earth monoantimonides show significant gaps between the upper and lower bands at the X point. Furthermore, similar to the previously reported results of LaBi, a Dirac-like structure was observed at the Γ point in YSb, CeSb, and GdSb, compounds showing relatively high magnetoresistance. This Dirac-like structure may contribute to the unusually large magnetoresistance in these compounds.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2019

Well‐Dispersed Nickel‐ and Zinc‐Tailored Electronic Structure of a Transition Metal Oxide for Highly Active Alkaline Hydrogen Evolution Reaction

Abstract The practical scale‐up of renewable energy technologies will require catalysts that are more efficient and durable than present ones. This is, however, a formidable challenge that will demand a new capability to tailor the electronic structure. Here, an original electronic structure tailoring of CoO by Ni and Zn dual doping is reported. This changes it from an inert material into one that is highly active for the hydrogen evolution reaction (HER). Based on combined density functional theory calculations and cutting‐edge characterizations, it is shown that dual Ni and Zn doping is responsible for a highly significant increase in HER activity of the host oxide. That is, the Ni dopants cluster around surface oxygen vacancy of the host oxide and provide an ideal electronic surface structure for hydrogen intermediate binding, while the Zn dopants distribute inside the host oxide and modulate the bulk electronic structure to boost electrical conduction. As a result, the dual‐doped Ni, Zn CoO nanorods achieve current densities of 10 and 20 mA cm −2 at overpotentials of, respectively, 53 and 79 mV. This outperforms reported state‐of‐the‐art metal oxide, metal oxide/metal, metal sulfide, and metal phosphide catalysts.

Ling, Tao↗
DOE OSTI2015

First principle study of structural, electronic and magnetic properties of zigzag boron nitride nanoribbon: Role of vacancies

We study the effect of vacancies on the structural, electronic and magnetic properties of zigzag boron nitride nanoribbon (ZBNNR) by using first principle calculations. We find that the shift of the vacancies with respect to the ribbon edges causes change in the structural geometry, electronic structure and magnetization of ZBNNR. These vacancies also produce band gap modulation and consequently results the magnetization of ZBNNR.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2015

Electronic structure and ground-state properties of Na{sub 2}Po: A first-principles study

Self-consistent scalar-relativistic band structure calculations have been performed to investigate the electronic structure and ground-state properties of Na{sub 2}Po in cubic antifluorite (anti-CaF{sub 2}-type) structure using the linear muffin-tin orbital in its tight-binding representation (TB-LMTO) method. Ground state properties such as equilibrium lattice constant and bulk modulus were calculated. The results of the electronic structure calculations show that Na{sub 2}Po is direct bandgap semiconductor.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

Real-space visualization of conformation-independent oligothiophene electronic structure

We present scanning tunneling microscopy and spectroscopy (STM/STS) investigations of the electronic structures of different alkyl-substituted oligothiophenes on the Au(111) surface. STM imaging showed that on Au(111), oligothiophenes adopted distinct straight and bent conformations. By combining STS maps with STM images, we visualize, in real space, particle-in-a-box-like oligothiophene molecular orbitals. We demonstrate that different planar conformers with significant geometrical distortions of oligothiophene backbones surprisingly exhibit very similar electronic structures, indicating a low degree of conformation-induced electronic disorder. The agreement of these results with gas-phase density functional theory calculations implies that the oligothiophene interaction with the Au(111) surface is generally insensitive to molecular conformation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Ab initio study of structural, electronic, magnetic alloys: XTiSb (X = Co, Ni and Fe)

Structural, electronic and magnetic properties of three semi-Heusler compounds of CoTiSb, NiTiSb and FeTiSb were calculated by the method (FP-LAPW) which is based on the DFT code WIEN2k. We used the generalized gradient approximation (GGA (06)) for the term of the potential exchange and correlation (XC) to calculate structural properties, electronic properties and magnetic properties. Structural properties obtained as the lattice parameter are in good agreement with the experimental results available for the electronic and magnetic properties was that: CoTiSb is a semiconductor NiTiSb is a metal and FeTiSb is a half-metal ferromagnetic.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2021

Local electronic structure of histidine in aqueous solution

Here, the local electronic structure of aqueous histidine, an amino acid important in nature and biology, is revealed by aerosol X-ray photoemission spectroscopy. A detailed picture of the photoionization dynamics emerges by tuning the pH of the aqueous solution from which the aerosols are generated, allowing us to report the X-ray photoelectron spectroscopy (XPS) of histidine. Assignment of the experimental photoelectron spectra of the C1s and N1s levels allows the determination of the protonation state of histidine in these aqueous aerosols and is confirmed by density functional calculations. XPS spectra show that at pH = 1, both imidazole and amine group nitrogens are protonated, at pH = 7, the amine group nitrogen is protonated and the carboxyl group carbon is deprotonated resulting in a zwitterionic structure, and at pH = 13, only the carboxyl group remains deprotonated. Comparison of these results with previous experimental and theoretical results suggests that X-ray spectroscopy on aqueous aerosols can provide a convenient and simple way of probing their electronic structure in aqueous solutions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Topological electronic structure of YbMg 2 Bi 2 and CaMg 2 Bi 2

Zintl compounds have been extensively studied for their outstanding thermoelectric properties, but their electronic structure remains largely unexplored. Here, we present a detailed investigation of the electronic structure of the isostructural thermopower materials YbMg 2 Bi 2 and CaMg 2 Bi 2 using angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT). The ARPES results show a significantly smaller Fermi surface and Fermi velocity in CaMg 2 Bi 2 than in YbMg 2 Bi 2 . Our ARPES results also reveal that in the case of YbMg 2 Bi 2 , Yb- 4 f states reside well below the Fermi level and likely have a negligible impact on transport properties. To properly model the position of 4f-states, as well as the overall electronic structure, a Hubbard U at the Yb sites and spin-orbit coupling (SOC) have to be included in the DFT calculations. The theoretical results reveal that both materials belong to a Z 2 topological class and host topological surface states around EF. Due to the intrinsic hole doping, the topological states reside above the Fermi level, inaccessible by ARPES. Our results also suggest that in addition to SOC, vacancies and the resulting hole doping play an important role in the transport properties of these materials.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Synthesis, Crystal and Electronic Structures, and Optical Properties of (CH 3 NH 3 ) 2 CdX 4 (X = Cl, Br, I)

Here, we report the synthesis, crystal and electronic structures, as well as optical properties of the hybrid organic–inorganic compounds MA 2 CdX 4 (MA = CH 3 NH 3 ; X = Cl, Br, I). MA 2 CdI 4 is a new compound, whereas, for MA 2 CdCl 4 and MA 2 CdBr 4 , structural investigations have already been conducted but electronic structures and optical properties are reported here for the first time. Single crystals were grown through slow evaporation of MA 2 CdX 4 solutions with optimized conditions yielding mm-sized colorless (X = Cl, Br) and pale yellow (X = I) crystals. Single crystal and variable temperature powder X-ray diffraction measurements suggest that MA 2 CdCl 4 forms a 2D layered perovskite structure and has two structural transitions at 283 and 173 K. In contrast, MA 2 CdBr 4 and MA 2 CdI 4 adopt 0D K 2 SO 4 -derived crystal structures based on isolated CdX 4 tetrahedra and show no phase transitions down to 20 K. The contrasting crystal structures and chemical compositions in the MA 2 CdX 4 family impact their air stabilities, investigated for the first time in this work; MA 2 CdCl 4 is air-stable, whereas MA 2 CdBr 4 and MA 2 CdI 4 partially decompose when left in air. Optical absorption measurements suggest that MA 2 CdX 4 have large optical band gaps above 3.9 eV. Room temperature photoluminescence spectra of MA 2 CdX 4 yield broad peaks in the 375–955 nm range with full width at half-maximum values up to 208 nm. These PL peaks are tentatively assigned to self-trapped excitons in MA 2 CdX 4 following the crystal and electronic structure considerations. The bands around the Fermi level have small dispersions, which is indicative of high charge localization with significant exciton binding energies in MA 2 CdX 4 . On the basis of our combined experimental and computational results, MA 2 CdX 4 and related compounds may be of interest for white-light-emitting phosphors and scintillator applications.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2013

The Y{sub 5−x}Mg{sub 24+x}(1.08(4)≤x≤1.30(1)) series and a ternary derivative Ce{sub 6.9}Y{sub 12.5(7)}Mg{sub 92.2}: A comparison of their crystal and electronic structures

The Y{sub 5−x}Mg{sub 24+x} series and a ternary derivative, Ce{sub 0.36}Y{sub 0.64(2)}Mg{sub 4.76}, have been synthesized using high-temperature methods and characterized by both powder and single crystal X-ray diffraction. The Y{sub 5−x}Mg{sub 24+x} series upon quenching from 580 °C crystallizes over the range 1.08(4)≤x≤1.30(1) in the cubic α-Mn structure type (I4{sup ¯}3m, Z=2, Pearson symbol cI58) with mixed occupancy of Y and Mg at the 8c site. As Mg content increases, the corresponding lattice parameter a increases from 11.2337(6) Å for Y{sub 3.92(4)}Mg{sub 25.08} to 11.256(2) Å for Y{sub 3.70(1)}Mg{sub 25.30}. Attempts to replace Y atoms with larger, isovalent Ce atoms yielded Ce{sub 6.9}Y{sub 12.5(7)}Mg{sub 92.2}(=Ce{sub 0.36}Y{sub 0.64(2)}Mg{sub 4.76}), which adopts a defect Sm{sub 11}Cd{sub 45} structure type (F4{sup ¯}3m, Z=8, Pearson symbol cF446.4), with a lattice parameter a=22.443(2) Å that is nearly twice larger than those of the Y{sub 5−x}Mg{sub 24+x} series. The complex crystal structure of this ternary derivative can be described as an ordered, body-centered cubic packing of four chemically and structurally distinctive “nested-polyhedra,” two 27-atom and two 29-atom, α-Mn units. Electronic structure calculations show nearly free electron like behavior, but with a distinctive pseudogap in the density of states curve for the ternary system. - Graphical abstract: Reported is the Mg-rich intermetallic compounds Y{sub 5−x}Mg{sub 24+x} series adopting the cubic α-Mn type structure and its complex ternary derivative Ce{sub 6.9}Y{sub 12.5}Mg{sub 92.2} crystallized in a defect Sm{sub 11}Cd{sub 45} type structure with a nearly twice larger lattice parameter than those of the Y{sub 5−x}Mg{sub 24+x} series. Electronic structure calculations show nearly free electron like behavior, but with a distinctive pseudogap in the density of states curve for the ternary system. Highlights: • The Y{sub 5−x}Mg{sub 24+x} series and Ce{sub 6.9}Y{sub 12.5}Mg{sub 92.2} have been synthesized. • Ce{sub 6.9}Y{sub 12.5}Mg{sub 92.2} is seen as a body-centered cubic packing of “nested-polyhedra”. • Electronic structures show nearly free electron like behavior.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Ab Initio Study of Atomic and Electronic Structure of Promising Ba4XMn3O12 (X = Nb, Ce, Pr) Oxides for Solar Thermochemical Hydrogen Production

The two-step metal oxide water-splitting cycle is one of the most viable approach for Solar Thermochemical Hydrogen (STCH) production. Challenges exist in finding suitable oxides that can satisfy thermodynamics of the STCH redox cycle under viable range of temperatures and partial pressures. Recently, BXM family members, i.e., Ba4NbMn3O12 (BNM), Ba4CeMn3O12 (BCM), Ba4PrMn3O12 (BPM) are discovered to exhibit promising STCH performance. However, the magnetic degrees of freedom of their experimental crystal structures is not characterized, and only hypothetical models exist for their electronic structure. We performed Monte-Carlo sampling for the magnetic spin arrangement of Mn atoms to provide explicit atomic structure models for their ground state 12R polytype and determined the most stable spin configuration for each member after structure relaxation using density functional theory (DFT) calculations. We also elucidate the most stable charge configuration (Mn3+/Mn4+ arrangement) for BNM among the existing hypothesis in literature. We investigate these strongly correlated oxides using different levels of theory (DFT+U, Hybrid-DFT) to develop better understanding of their electronic structure. These calculations allowed us to develop a model based on molecular orbital interactions that help explain the observed changes in their experimental x-ray spectroscopy measurements. Thereby, help link differences in electronic structure of BXM family members to their varying water-splitting behavior. These structure models will further facilitate future in-depth defect studies to model STCH redox cycle of these oxides.

atomic and magnetic structure↗
DOE OSTI2015

Electronic Structure of Buried Interfaces - Oral Presentation [Slides]

In the electronics behind computer memory storage, the speed and size are dictated by the performance of permanent magnets inside devices called read heads. Complicated magnets made of stacked layers of thin films can be engineered to have properties that yield more energy storage and faster switching times compared to conventional iron or cobalt magnets. The reason is that magnetism is a result of subtle interactions amongst electrons; just how neurons come together on large scales to make cat brains and dog brains, ensembles of electrons interact and become ferromagnets and paramagnets. These interactions make magnets too difficult to study in their entirety, so I focus on the interfaces between layers, which are responsible for the coupling materials physicists hope to exploit to produce next-generation magnets. This project, I study a transition metal oxide material called LSCO, Lanthanum Cobaltite, which can be a paramagnet or a ferromagnet depending on how you tweak the electronic structure. It exhibits an exciting behavior: its sum is greater than the sum of its parts. When another similar material called a LSMO, Lanthanum Manganite, is grown on top of it, their interface has a different type of magnetism from the LSCO or the LSMO! I hope to explain this by demonstrating differently charged ions in the interface. The typical method for quantifying this is x-ray absorption, but all conventional techniques look at every layer simultaneously, averaging the interfaces and the LSCO layers that we want to characterize separately. Instead, I must use a new reflectivity technique, which tracks the intensity of reflected x-rays at different angles, at energies near the absorption peaks of certain elements, to track changes in the electronic structure of the material. The samples were grown by collaborators at the Takamura group at U.C. Davis and probed with this “resonant reflectivity” technique on Beamline 2-1 at the Stanford Synchrotron Radiation Lightsource. This project was funded by the Department of Energy and supported by the SLAC National Accelerator Laboratory. Preliminary results suggest that different ionic charges are indeed responsible for the different magnetic properties at the interface, which is promising because charge is easy to control. Once scientists understand how to tune the magnetic properties of materials like LSCO and LSMO, industries get closer to designing the magnets that will soon revolutionize consumer electronics.

36 MATERIALS SCIENCE↗
DOE OSTI2013

Analysis of the electronic structure of ZrO{sub 2} by Compton spectroscopy

The electronic structure of ZrO{sub 2} is studied using the Compton scattering technique. The first-ever Compton profile measurement on polycrystalline ZrO{sub 2} was obtained using 59.54 keV gamma-rays emanating from the {sup 241}Am radioisotope. To explain the experimental data, we compute theoretical Compton profile values using the method of linear combination of atomic orbitals in the framework of density functional theory. The correlation scheme proposed by Perdew-Burke-Ernzerhof and the exchange scheme of Becke are considered. The ionic-model-based calculations for a number of configurations, i.e., Zr{sup +x}(O{sup -x/2}){sub 2} (0 {<=} x {<=} 2), are also performed to estimate the charge transfer on compound formation, and the study supports transfer of 1.5 electrons from Zr to O atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Efficient Modeling of Structural, Electronic, and Optical Properties of Silver and Gold Metal Nanoclusters and Alloys Using Optimized SCC-DFTB Parameters

Computation of optical properties using conventional time-dependent density functional theory (TD-DFT) is time-consuming and memory-intensive. In this study, we investigate the accuracy and efficiency of the density functional tight binding (DFTB) framework with newly optimized Slater–Koster (SK) parameters for modeling the structural, electronic properties, and absorption spectra of silver and gold nanoclusters and their alloys. Our investigation of the ground state (GS) properties demonstrates that the newly developed GS-SK parameters enable DFTB to closely approximate DFT-calculated bond lengths for octahedron, tetrahedron, icosahedra, and truncated octahedron with sizes Ag n /Au n (n = 19, 20, 38, 55), nanoclusters and Ag 20 /Au 20 nanoalloys, with a maximum deviation of approximately 0.15 Å. Formation energy results indicate that the GS-SK parameters can closely estimate changes in formation energies with alloy composition, and the comparison of electronic structures for Ag 20 , Au 20 , and AgAu alloy nanoclusters using the DFTB approximation reveals good agreement in the projected density of states (DOS) profiles and energy levels. A second set of SK parameters, ES-SK, has been developed to describe excited state (ES) properties, including the absorption spectra of silver octahedron Ag 19 , tetrahedral Ag n (n = 20, 56, 84), truncated octahedron Ag 38 , and icosahedra Ag 55 closed-shell clusters and their gold and alloy counterparts over a broad range of alloy compositions. This parametrization uses TD-DFTB calculations and fine-tunes the d and p eigenvalues by comparing them to reference absorption spectra from first-principles TD-DFT. This enables the generation of absorption spectra that closely match the reference spectra when plasmon excitation is dominant, as demonstrated by studying the plasmonic properties of icosahedral Ag n and Au n (n = 309 and 561) nanoparticles. This includes the rapid loss in plasmon quality when Au partially replaces Ag in alloy clusters. Furthermore, these results provide a foundation for addressing computational bottlenecks in plasmonics and with new prospects for applications in the quantum plasmonics for bimetallic alloys.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

Atomic and electronic structure of Ti substitution in Ca 3 o 4 O 9

We examine the role of Ti doping in the incommensurately layered thermoelectric oxide material Ca 3 Co 4 O 9 (CCO). The measured Seebeck coefficient of S = 135 μV/K in Ti-doped CCO thin films of composition Ca 3 Co 3.8 Ti 0.2 O 9 indicates no significant enhancement of S compared to pristine CCO, thus confirming prior experimental results. Using a combination of aberration-corrected scanning transmission electron microscopy, electron energy-loss spectroscopy and first-principles computations, we determine the atomic and electronic structures of Ti-doped CCO, including the preferred location of Ti dopants and valence states of Ti and Co atoms. Our findings on the structural, electronic, and transport properties of the Ti-doped CCO are discussed in light of the previously published results.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2020

Excited-state electronic structure of molecules using many-body Green’s functions: Quasiparticles and electron–hole excitations with VOTCA-XTP

Here, we present the open-source VOTCA-XTP software for the calculation of the excited-state electronic structure of molecules using many-body Green’s function theory in the GW approximation with the Bethe–Salpeter equation (BSE). This work provides a summary of the underlying theory and discusses the details of its implementation based on Gaussian orbitals, including resolution-of-identity techniques and different approaches to the frequency integration of the self-energy or acceleration by offloading compute-intensive matrix operations using graphics processing units in a hybrid OpenMP/Cuda scheme. A distinctive feature of VOTCA–XTP is the capability to couple the calculation of electronic excitations to a classical polarizable environment on an atomistic level in a coupled quantum- and molecular-mechanics (QM/MM) scheme, where a complex morphology can be imported from Molecular Dynamics simulations. The capabilities and limitations of the GW–BSE implementation are illustrated with two examples. First, we study the dependence of optically active electron–hole excitations in a series of diketopyrrolopyrrole-based oligomers on molecular-architecture modifications and the number of repeat units. Second, we use the GW–BSE/MM setup to investigate the effect of polarization on localized and intermolecular charge-transfer excited states in morphologies of low-donor content rubrene–fullerene mixtures. These showcases demonstrate that our implementation currently allows us to treat systems with up to 2500 basis functions on regular shared-memory workstations, providing accurate descriptions of quasiparticle and coupled electron–hole excited states of various characters on an equal footing.

74 ATOMIC AND MOLECULAR PHYSICS↗