Detecting stable adsorbates of (1S)-camphor on Cu(111) with Bayesian optimization

• Jari Järvi,
• Patrick Rinke and
• Milica Todorović

Beilstein J. Nanotechnol. 2020, 11, 1577–1589, doi:10.3762/bjnano.11.140

• fast to compute, but they cannot accurately model hybrid materials, in which atomic interactions often feature a mixture of covalent and dispersive bonding, with charge transfer and polarization effects. Instead, we must employ quantum mechanical methods, such as density-functional theory (DFT) [12][13

• ][33][34] provides a solution to the structure search conundrum. With BOSS, we adopt the aforementioned approach (ii) and construct the complete PES using a small number of energy points. To demonstrate the capabilities of BOSS, we apply it with DFT to the adsorption of (1S)-camphor (C10H16O, hereafter

• iteratively with active learning, and identifies the stable structures in the minima of the PES. In this work, we apply BOSS with DFT for accurate sampling of the energy points. In the following, we introduce the four-step process (Figure 1) of structure detection with BOSS and DFT, in analogy to [31]. We

Adsorption and self-assembly of porphyrins on ultrathin CoO films on Ir(100)

• Feifei Xiang,
• Tobias Schmitt,
• Marco Raschmann and
• M. Alexander Schneider

Beilstein J. Nanotechnol. 2020, 11, 1516–1524, doi:10.3762/bjnano.11.134

• films on Ir(100) by scanning tunneling microscopy (STM) and density functional theory (DFT). The two substrates differ greatly with respect to their structural and potential-energy landscape corrugation with immediate consequences for adsorption and self-assembly of the molecules studied. On both films

• -PAW general gradient approximation [33]. To account for dispersion forces the zero damping DFT-D3 correction of Grimme et al. was used [34]. Slabs were constructed from two layers of iridium and one or two bilayers of cobalt oxide. For the iridium lattice the relaxed DFT-D3 parameter (a = 3.835 Å) was

• between functionalized porphyrins has also been observed on metal surfaces [27]. Discussion To gain insight into the reasons behind the experimental findings, DFT calculations were performed. Both, 1 and 2 were structurally relaxed on the 1BL CoO film in order to find the adsorption geometry. The lowest

Controlling the electronic and physical coupling on dielectric thin films

• Philipp Hurdax,
• Michael Hollerer,
• Larissa Egger,
• Georg Koller,
• Xiaosheng Yang,
• Anja Haags,
• Serguei Soubatch,
• Frank Stefan Tautz,
• Mathias Richter,
• Alexander Gottwald,
• Peter Puschnig,
• Martin Sterrer and
• Michael G. Ramsey

Beilstein J. Nanotechnol. 2020, 11, 1492–1503, doi:10.3762/bjnano.11.132

• ]. It should be noted that the occupation of the LUMO is predicted to reduce the torsional angle in the molecule, given that it has a bonding character with respect to the phenyl rings (see Figure 3c) [33]. However, this is not a sufficient condition for planarization. Density functional theory (DFT

• overlap between the phenyl rings. This will cause an increase in the energy spread of the π bands, resulting in a decrease in the ionization potential and an increase in the electron affinity. Gas phase DFT calculations show that the EA of planar 6P (1.74 eV) is indeed 0.3 eV higher than the EA of twisted

Self-assembly and spectroscopic fingerprints of photoactive pyrenyl tectons on hBN/Cu(111)

• Domenik M. Zimmermann,
• Knud Seufert,
• Luka Ðorđević,
• Tobias Hoh,
• Sushobhan Joshi,
• Tomas Marangoni,
• Davide Bonifazi and
• Willi Auwärter

Beilstein J. Nanotechnol. 2020, 11, 1470–1483, doi:10.3762/bjnano.11.130

• characterizing a family of pyridin-4-ylethynyl-functionalized pyrene derivatives in different environments. UV–vis measurements in toluene solutions revealed absorption at wavelengths consistent with density functional theory (DFT) calculations, while emission experiments showed a high fluorescence quantum yield

• experiments, the photophysical characterization in solution, and the DFT modeling (in vacuum and with toluene solvation) evidence a reduction of the molecular gap when proceeding from di- to tetrasubstituted pyrene derivatives, but with effects that are different depending on the chemical surrounding. Results

• effect of the substitution on the electronic properties of the pyrene core, DFT calculations were performed (B3LYP/6-31G** level of theory, in vacuum). The frontier Kohn-Sham orbitals of pyrene and the di- and tetrasubstituted (pyridin-4-ylethynyl)pyrenes 1, 2, and 3 are shown in Figure 1b (see also

Protruding hydrogen atoms as markers for the molecular orientation of a metallocene

• Linda Laflör,
• Michael Reichling and
• Philipp Rahe

Beilstein J. Nanotechnol. 2020, 11, 1432–1438, doi:10.3762/bjnano.11.127

• ), Cu(110), and Cu3N/Cu(110) surfaces [20] as well as on the insulator surfaces calcite(104) [21] and CaF2(111) [22]. An eclipsed ferrocene conformation was found to be predominant on the metallic surfaces [20] and on calcite(104) [21]. On CaF2(111) surfaces, density functional theory (DFT) calculations

• atoms were used as probe particles and frequency-shift Δf data were calculated for an oscillation amplitude of 0.5 nm. Lateral and vertical stiffness were chosen as 0.5 and 20 N/m, respectively. FDCA molecular models in the DFT-optimised geometries (using geo 1 and geo 2 from [22], see Figure 1a,b) were

• Figure 2e) evolve on one side of a sharp line connecting the weights of the dumbbells. For an interpretation of the NC-AFM contrast, we run simulations based on the probe particle model [23] for three molecules aligned along , each molecule being in the DFT-optimised adsorption geometry geo 1 [22], as

Atomic defect classification of the H–Si(100) surface through multi-mode scanning probe microscopy

• Jeremiah Croshaw,
• Thomas Dienel,
• Taleana Huff and
• Robert Wolkow

Beilstein J. Nanotechnol. 2020, 11, 1346–1360, doi:10.3762/bjnano.11.119

• charged species by means of tip-induced liberation of an atomic hydrogen from the defect site. While our work presents a comprehensive understanding of the experimental nature of these defects, additional theoretical studies using more powerful techniques such as DFT is still needed to confirm the results

Structural and electronic properties of SnO₂ doped with non-metal elements

• Jianyuan Yu,
• Yingeng Wang,
• Yan Huang,
• Xiuwen Wang,
• Jing Guo,
• Jingkai Yang and
• Hongli Zhao

Beilstein J. Nanotechnol. 2020, 11, 1321–1328, doi:10.3762/bjnano.11.116

• reflectivity in the infrared region, and the reflectance of the crystals doped with N, C, S, and B decreased sequentially. Based on this theoretical calculations, F-doped SnO2 is found to be the best photoelectric material for preparing low-emissivity coatings. Keywords: density functional theory (DFT); doped

• dope SnO2. The calculations were carried out with the CASTEP software. In this paper, density functional theory (DFT) is used to analyze electronic structure and optical properties of SnO2 doped with non-metal elements. Crystal Structure Model and Calculation Method The SnO2 crystal has a tetragonal

• CASTEP program based on DFT. The Perdew–Burke–Ernzerhof (PBE) generalized gradient approximation (GGA) was selected as the exchange–correlation functional. The interaction between inner electrons and valence electrons was described by the OTFG ultra-soft pseudopotential. The valence electronic

Nonadiabatic superconductivity in a Li-intercalated hexagonal boron nitride bilayer

• Kamila A. Szewczyk,
• Izabela A. Domagalska,
• Artur P. Durajski and
• Radosław Szczęśniak

Beilstein J. Nanotechnol. 2020, 11, 1178–1189, doi:10.3762/bjnano.11.102

• ] and quantum information technology [44][45]. Currently, the most promising research seems to be the properties of the superconducting state in Li-intercalated hexagonal boron nitride bilayer (Li-hBN) compounds. Based on DFT calculations, it has been shown that the critical temperature (TC) of the

• resistance), the crossover to superconductivity (50% of the normal resistance), and the confinement of vortices, respectively. The important question is whether the Li-hBN bilayer system yield the high critical temperature that was suggested from DFT calculations (TC = 25 K) [41]. We think that this not the

• is quantified by the so-called Eliashberg function (α2F(ω)). The form of the Eliashberg function for a specific physical system can be determined theoretically through DFT calculations [58], or experimentally using the data provided by tunnel experiments [59][60]. The electron correlations (the

Straightforward synthesis of gold nanoparticles by adding water to an engineered small dendrimer

• Sébastien Gottis,
• Régis Laurent,
• Vincent Collière and
• Anne-Marie Caminade

Beilstein J. Nanotechnol. 2020, 11, 1110–1118, doi:10.3762/bjnano.11.95

• chemical signal. In addition, it has been shown that the 2JPP coupling constant values decrease when the electron-withdrawing power of the substituents decreases [55]. The density functional theory (DFT) calculations on free and Au-complexed P=N–P=S linkages have shown that a charge is transferred from the

Monolayers of MoS₂ on Ag(111) as decoupling layers for organic molecules: resolution of electronic and vibronic states of TCNQ

• Asieh Yousofnejad,
• Gaël Reecht,
• Nils Krane,
• Christian Lotze and
• Katharina J. Franke

Beilstein J. Nanotechnol. 2020, 11, 1062–1071, doi:10.3762/bjnano.11.91

• , we corroborate this assignment by simulating constant-height dI/dV maps of a free, flat-lying molecule. We first calculated the gas-phase electronic structure using density functional theory (DFT) calculations with the B3PW91 functional and the 6-31g(d,p) basis set as implemented in the Gaussian 09

• LUMO with the double U-shape being in very good agreement with the calculations of the tunneling matrix element. The very same signatures in the conductance map at 0.64 V suggest that this resonance stems from the LUMO as well. The DFT calculations show that the LUMO is non-degenerate. Hence, we can

• essentially shows the same elliptical shapes of the molecules as the STM image recorded in the electronic gap (Figure 4a). Our DFT calculations suggest that the next higher unoccupied orbitals lie 3 eV above the LUMO and show a pattern of nodal planes that are absent in the experiment. Additionally, given the

A new photodetector structure based on graphene nanomeshes: an ab initio study

• Babak Sakkaki,
• Hassan Rasooli Saghai,
• Ghafar Darvish and
• Mehdi Khatir

Beilstein J. Nanotechnol. 2020, 11, 1036–1044, doi:10.3762/bjnano.11.88

• Abstract Recent experiments suggest graphene-based materials as candidates in future electronic and optoelectronic devices. In this paper, we propose to investigate new photodetectors based on graphene nanomeshes (GNMs). Density functional theory (DFT) calculations are performed to gain insight into

• electronic and optical characteristics of various GNM structures. To investigate the device-level properties of GNMs, their current–voltage characteristics are explored by DFT-based tight-binding (DFTB) in combination with non-equilibrium Green’s function (NEGF) methods. Band structure analysis shows that

• makes it suitable for optical devices. Keywords: absorption spectra; DFT calculations; graphene nanomesh; graphene nanoribbon; photodetectors; Introduction Graphene monolayers with honeycomb crystal structure have unique electrical and optical properties and have received a lot of attention recently

Three-dimensional solvation structure of ethanol on carbonate minerals

• Hagen Söngen,
• Ygor Morais Jaques,
• Peter Spijker,
• Christoph Marutschke,
• Stefanie Klassen,
• Ilka Hermes,
• Ralf Bechstein,
• Lidija Zivanovic,
• John Tracey,
• Adam S. Foster and
• Angelika Kühnle

Beilstein J. Nanotechnol. 2020, 11, 891–898, doi:10.3762/bjnano.11.74

• has been investigated theoretically by using both density functional theory (DFT) [12][13] and molecular dynamics (MD) simulations [14][15][16][17]. It has been found that ethanol molecules strongly bind towards calcite (10.4) terraces – even stronger than water [12][14][16][17]. Ethanol molecules

• isolated ethanol molecule on calcite obtained with DFT calculations [13]. Consequently, the hydrocarbon chains of the ethanol molecules point away from the surface. This results in one ethanol molecule per CaCO3 at the calcite (10.4) surface. The ordered first layer of ethanol molecules above the calcite

Adsorption behavior of tin phthalocyanine onto the (110) face of rutile TiO₂

• Lukasz Bodek,
• Mads Engelund,
• Aleksandra Cebrat and
• Bartosz Such

Beilstein J. Nanotechnol. 2020, 11, 821–828, doi:10.3762/bjnano.11.67

• measurements of single molecules reveal the coexistence of two conformations of molecules on the TiO2 surface. Density functional theory-based simulations (DFT) indicate that the difference originates from the position of the tin atom protruding from the molecule plane. The irreversible switching of Sn-up

• [6], CuPc [7][8][9][10], ZnPc [11], FePc [12] and H2Pc [13]), while their nonplanar counterparts such as SnPc have been rarely probed [14]. Spectroscopy studies or density functional theory (DFT) calculations of molecular species adsorbed onto titanium dioxide can be an arduous task, especially for

• interactions between SnPc molecules and the rutile surface, while DFT-based simulations combined with high-resolution STM images imply that a Sn-down geometry may be preferred as a consequence of steric adjustment between the molecular shape and the corrugated (110) surface. Experimental The experiment was

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

• indirect bandgaps. Bandgap energy values largely varying from 3.6 eV to 7.1 eV have been reported in the literature [84][85][86]. Theoretical calculations for the h-BN band structure also show significant differences in the eV values. Some density functional theory (DFT) in the local-density-approximation

• [112] and is thus a candidate for a spin qubit. Other modeling based on DFT and constrained DFT attributes the SPE to a VNCB defect [104]. In [97] few layers of exfoliated h-BN were studied under cathode-luminescence (CL) combined with a Hanbury Brown and Twiss interferometer to identify their SPE in

• 442 nm to 780 nm with operation from cryogenic to very high temperatures (1100 K). DFT was used to understand the origin of such broadband emission possible from defect states related to H, O, C, N, and B induced defects in bulk and monolayers indicating the emission-related defects population

Interfacial charge transfer processes in 2D and 3D semiconducting hybrid perovskites: azobenzene as photoswitchable ligand

• Nicole Fillafer,
• Tobias Seewald,
• Lukas Schmidt-Mende and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2020, 11, 466–479, doi:10.3762/bjnano.11.38

• characterized with NMR (1H, 13C) and electro-spray ionisation mass spectroscopy (ESIMS) the results of which can be found in Supporting Information File 1 (Figures S1–S4). Several methods were used to investigate the properties of the ligands in the absence of the perovskite as reference. DFT calculations were

• Information File 1, Figure S18. DOI for dissolved functionalized 3D particles and free ligands in MeOD. 1H NMR spectra can be seen in the Supporting Information File 1, Figure S21. Supporting Information NMR, ESIMS, UV–vis (kinetic) and PESA measurements, and DFT calculations of the free ligands; UV–vis

Atomic-resolution imaging of rutile TiO₂(110)-(1 × 2) reconstructed surface by non-contact atomic force microscopy

• Daiki Katsube,
• Shoki Ojima,
• Eiichi Inami and
• Masayuki Abe

Beilstein J. Nanotechnol. 2020, 11, 443–449, doi:10.3762/bjnano.11.35

• microscopy (STM) [10][11][12], transmission electron microscopy [13][14], and density functional theory (DFT) [15][16][17][18][19]. These studies have determined many surface properties such as structure, local defects, and adsorption sites. The (1 × 1) surface transforms to the (1 × 2) surface by oxygen

• the symmetric Ti2O3 model based on DFT calculations [24]. These two structural models have been widely accepted. Mochizuki et al. reported total reflection high-energy positron diffraction results for the (1 × 2) surface, which supported the asymmetric Ti2O3 model [25]. In contrast, our previous study

• DFT and STM and to investigate the bias dependence of simultaneous NC-AFM and STM images. This will be discussed elsewhere since the main subject of this article is the periodic line structure on the rutile TiO2(110)-(1 × 2) reconstructed surface. Our NC-AFM and STM imaging in the same area identified

DFT calculations of the structure and stability of copper clusters on MoS₂

• Cara-Lena Nies and
• Michael Nolan

Beilstein J. Nanotechnol. 2020, 11, 391–406, doi:10.3762/bjnano.11.30

• density functional theory (DFT) study of the adsorption of small Cun (n = 1–4) structures on 2D MoS2 as a model system. We find on a perfect MoS2 monolayer that a single Cu atom prefers an adsorption site above the Mo atom. With increasing nanocluster size the nanocluster binds more strongly when Cu atoms

• character of Cu nanoclusters is preserved. Keywords: copper (Cu); density functional theory (DFT); 2D materials; molybdenum disulfide (MoS2); thin film nucleation; Introduction Since the successful exfoliation of monolayers of graphene by Novoselov et al., 2D materials have gained a large interest in a

• out with density functional theory (DFT) using the Vienna ab initio simulation package (VASP) version 5.4 [34]. It uses 3D periodic boundary conditions and the spin-polarized generalized gradient approximation (GGA) using the Perdew–Burke–Ernzerhof (PBE) approximation to the exchange–correlation

Synthesis of amorphous and graphitized porous nitrogen-doped carbon spheres as oxygen reduction reaction catalysts

• Maximilian Wassner,
• Markus Eckardt,
• Andreas Reyer,
• Thomas Diemant,
• Michael S. Elsaesser,
• R. Jürgen Behm and
• Nicola Hüsing

Beilstein J. Nanotechnol. 2020, 11, 1–15, doi:10.3762/bjnano.11.1

• be correlated with the ORR activity [17][18][19][20][21], is only slightly lower for nitriding at 1000 °C compared to nitriding at 700 °C. Hence, none of these different nitrogen configurations can simply explain the trend in the ORR activity. This agrees with the results of DFT-based calculations of

Air oxidation of sulfur mustard gas simulants using a pyrene-based metal–organic framework photocatalyst

• Ghada Ayoub,
• Mihails Arhangelskis,
• Xuan Zhang,
• Florencia Son,
• Timur Islamoglu,
• Tomislav Friščić and
• Omar K. Farha

Beilstein J. Nanotechnol. 2019, 10, 2422–2427, doi:10.3762/bjnano.10.232

• –Teller (BET) surface area of 1325 m2/g (Figure S4, Supporting Information File 1) [44]. The pore size analysis using DFT model revealed pores of approximately 11 Å, which is suitable for diffusion of CEES molecules into the pores of NU-400. The solid-state UV–vis spectrum of NU-400 reveals that the

Improvement of the thermoelectric properties of a MoO₃ monolayer through oxygen vacancies

• Wenwen Zheng,
• Wei Cao,
• Ziyu Wang,
• Huixiong Deng,
• Jing Shi and
• Rui Xiong

Beilstein J. Nanotechnol. 2019, 10, 2031–2038, doi:10.3762/bjnano.10.199

• -principles calculations. The calculations of the electrical properties of the MoO3 monolayer are performed using density functional theory (DFT) as implemented in the Vienna ab initio simulation package (VASP) code [18][19]. We utilize the generalized gradient approximation (GGA) of the Perdew–Burke

First principles modeling of pure black phosphorus devices under pressure

• Ximing Rong,
• Zhizhou Yu,
• Zewen Wu,
• Junjun Li,
• Bin Wang and
• Yin Wang

Beilstein J. Nanotechnol. 2019, 10, 1943–1951, doi:10.3762/bjnano.10.190

• investigate the quantum transport of pure BP devices within the framework of combination of non-equilibrium Green’s function (NEGF) and density functional theory (DFT) [33][34]. The manuscript is organized as follows: In section “Simulation Details”, we show the pure zigzag and armchair BP nanodevices and

• the size of the largest structures with a pressure region of 24L is already compatible with the practical scale of a transistor. In our investigation, two different DFT codes, VASP [35][36] and NanoDCal [33][34], were used to model the electric behavior and quantum transport of the BP devices under

• direction, and 2.102 Å in the vertical direction between two non-equivalent P atomic layers, which is in good agreement with the recognized DFT results [32]. The quantum transport properties of BP devices were implemented by the transport package NanoDCal, which is based on the standard NEGF-DFT method [33

Charge-transfer interactions between fullerenes and a mesoporous tetrathiafulvalene-based metal–organic framework

• Manuel Souto,
• Joaquín Calbo,
• Samuel Mañas-Valero,
• Aron Walsh and
• Guillermo Mínguez Espallargas

Beilstein J. Nanotechnol. 2019, 10, 1883–1893, doi:10.3762/bjnano.10.183

• electron-donor TTF ligand is studied in detail by means of different spectroscopic techniques and density functional theory (DFT) calculations. Importantly, gas sorption measurements demonstrate that sorption capacity is maintained after encapsulation of fullerenes, whereas the electrical conductivity is

• , respectively). Theoretical calculations In order to get further insight into the donor–acceptor interactions between C60 and the TTF-based MOF, theoretical calculations were performed under the density functional theory (DFT). The MUV-2 framework was modelled as previously described [53], with a high-spin Fe

• (2.5 Å, Figure 5). Analysis of the NCI index allows for the visualization of the noncovalent interactions between the TTFTB ligand and the C60 guest, showing a significantly larger NCI surface for conformer B compared to conformer A (Figure 5b). Accurate hybrid DFT molecular calculations including

Long-term entrapment and temperature-controlled-release of SF₆ gas in metal–organic frameworks (MOFs)

• Hana Bunzen,
• Andreas Kalytta-Mewes,
• Leo van Wüllen and
• Dirk Volkmer

Beilstein J. Nanotechnol. 2019, 10, 1851–1859, doi:10.3762/bjnano.10.180

• temperature-modulated thermogravimetric analysis. In order to obtain more realistic energy values, constrained geometry plane wave DFT+D calculations were performed for four different configurations (“min”, “TS”, “centre” and “start/end”) as marked in Figure 5a. For this, the starting configurations were

• extracted from the previous force field scan trajectory and all atomic positions were allowed to relax during subsequent optimization steps, except for the position of the sulfur atom of SF6, which was fixed at the corresponding c/N coordinate of the transition path. The PW-DFT+D calculations were performed

• with the CASTEP code [37] employing the PBE functional [38] and on-the-fly generated ultrasoft pseudopotentials (energy cutoff: 570 eV). Two different correction methods were included in all DFT calculations in order to account for dispersion interactions. The total energy values of these are shown in

Giant magnetoresistance ratio in a current-perpendicular-to-plane spin valve based on an inverse Heusler alloy Ti₂NiAl

• Yu Feng,
• Zhou Cui,
• Bo Wu,
• Jianwei Li,
• Hongkuan Yuan and
• Hong Chen

Beilstein J. Nanotechnol. 2019, 10, 1658–1665, doi:10.3762/bjnano.10.161

• utilizing a density functional theory (DFT)-based Vienna ab-initio simulation package (VASP) [31][32]. Ti (3d24s2), Ni (3d84s2), Al (3s23p1) and Ag (4d105s1) were chosen to be the valence electron configurations. The exchange-correlation interaction is described by the Perdew–Burke–Ernzerhof (PBE

Kelvin probe force microscopy work function characterization of transition metal oxide crystals under ongoing reduction and oxidation

• Dominik Wrana,
• Karol Cieślik,
• Wojciech Belza,
• Christian Rodenbücher,
• Krzysztof Szot and
• Franciszek Krok

Beilstein J. Nanotechnol. 2019, 10, 1596–1607, doi:10.3762/bjnano.10.155

• recently proved to be a Ti-enriched layer on TiO2-terminated SrTiO3(100) [30][40]. The electronic structures of both terminations are much different – the DFT calculated work function values are 1.92 eV and 4.48 eV for SrO and TiO2, respectively [14], obtained for the pure surfaces without vacancies. In

• one terrace may be expected, which can contribute to the observed small decrease in the WF near the step edges. In terms of the absolute work function of TiO2-terminated SrTiO3(100), the obtained value of 3.12(18) eV, averaged across a number of images, is close to this postulated by DFT (3.39 eV) for