Ca_n neutral clusters: a two-step G₀W₀ and DFT benchmark

• Sunila Bakhsh,
• Sameen Aslam,
• Muhammad Khalid,
• Muhammad Sohail,
• Sundas Zafar,
• Sumayya Abdul Wadood,
• Kareem Morsy and
• Muhammad Aamir Iqbal

Beilstein J. Nanotechnol. 2024, 15, 1010–1016, doi:10.3762/bjnano.15.82

• /bjnano.15.82 Abstract Electronic and structural properties of calcium clusters with a varying size range of 2–20 atoms are studied using a two-step scheme within the GW and density functional theory (DFT) with generalized gradient approximation (GGA). The GGA overestimates the binding energies, optimized

• technological advancements [2]. We used the DFT + GW scheme to investigate the electronic properties and structures of neutral Can (n = 2–20) clusters. From the DFT [17][18], one can obtain the accurate binding energies of the clusters, whereas the study of electronic properties from the GW approximation

• promises high accuracy in studying the excitation properties of the systems under consideration [19]. Despite the wide availability of theoretical and experimental work on Ca clusters, no GW studies have been performed on neutral calcium clusters to the best of our knowledge. Computational Method Here, we

Investigating structural and electronic properties of neutral zinc clusters: a G₀W₀ and G₀W₀Г₀⁽¹⁾ benchmark

• Sunila Bakhsh,
• Muhammad Khalid,
• Sameen Aslam,
• Muhammad Sohail,
• Muhammad Aamir Iqbal,
• Mujtaba Ikram and
• Kareem Morsy

Beilstein J. Nanotechnol. 2024, 15, 310–316, doi:10.3762/bjnano.15.28

• clusters, such as Zn2, the results significantly underestimate the experimentally measured IPs. State-of-the-art approaches, such as GW approximation, have been proven to provide accurate IPs and electron affinity (EA) values for various clusters [9][10][11][12]. Determining the ground states of clusters

• properties of the clusters. Previous attempts to study the electronic properties of Zn clusters based on ∆-SCF methods tended to underestimate the ionization energies of the clusters as the size grew. State-of-the-art techniques, such as the GW method, can effectively describe the electronic properties of

• reported literature shows that IP and Egap are also slightly lower than those of the neighboring clusters [7]. The GW scheme has also been proven effective for the description of accurate bandgaps. A comparison of the energy gaps is presented in Figure 4, in which the results from reported literature is

An investigation on the drag reduction performance of bioinspired pipeline surfaces with transverse microgrooves

• Weili Liu,
• Hongjian Ni,
• Peng Wang and
• Yi Zhou

Beilstein J. Nanotechnol. 2020, 11, 24–40, doi:10.3762/bjnano.11.3

• = 1,2,3; ui, uj were the speed of different coordinate directions (m/s); ρ was the density of fluid (kg/m3); was the Reynolds stress; and Gk was the turbulent kinetic energy produced by the velocity gradient. Further, Gw was generated by the ω equation; Γk, Γω were the effective diffusion terms of k and

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

• monolayer BP with RC equal to 0,15%, and 30%, respectively. When RC = 0, a direct bandgap of ca. 0.91 eV appears at the Γ point, which is in agreement with several theoretical works [12][32]. Although this bandgap is smaller than that measured in experiments [4][11] and obtained from the GW method [12], the

Computational exploration of two-dimensional silicon diarsenide and germanium arsenide for photovoltaic applications

• Sri Kasi Matta,
• Chunmei Zhang,
• Yalong Jiao,
• Anthony O'Mullane and
• Aijun Du

Beilstein J. Nanotechnol. 2018, 9, 1247–1253, doi:10.3762/bjnano.9.116

• studied using Green’s function, GW-Bethe–Salpeter equation (BSE) approach implemented in VASP code [23][29][30][31]. The GW calculations were performed with a 13 × 5 × 1 k-grid, the energy cut-off for response function is set at 100 both in GW and BSE approach for exact compatibility. Over and above the

• GW results, the BSE method was adopted to obtain the light absorption spectrum [21][22] and the optical band gap. BSE was solved by using the ten highest valance bands and ten lowest conduction bands and with a 13 × 5 × 1 k-grid. Using the band gaps obtained from GW and BSE functional methods the

• ) GW-band structures and (b,d) BSE-optical absorption spectra of SiAs2 and GeAs2, respectively. Calculated structural parameters of SiAs2 and GeAs2 compared with the experimental values. Calculated band gaps of SiAs2 and GeAs2 for bulk, bilayers and monolayers. Supporting Information Supporting

High-contrast and reversible scattering switching via hybrid metal-dielectric metasurfaces

• Jonathan Ward,
• Khosro Zangeneh Kamali,
• Lei Xu,
• Guoquan Zhang,
• Andrey E. Miroshnichenko and
• Mohsen Rahmani

Beilstein J. Nanotechnol. 2018, 9, 460–467, doi:10.3762/bjnano.9.44

• the related electric near-field distributions in the silicon disk for a plane wave with λFW = 1235 nm at I0 = 1 GW/cm2. As can be seen from Figure 6a, the efficiency of third harmonic generation can be enhanced by one order of magnitude due to the emergence of the Fano-like resonance during the

Two-dimensional silicon and carbon monochalcogenides with the structure of phosphorene

• Dario Rocca,
• Ali Abboud,
• Ganapathy Vaitheeswaran and
• Sébastien Lebègue

Beilstein J. Nanotechnol. 2017, 8, 1338–1344, doi:10.3762/bjnano.8.135

• monochalcogenides, some preliminary remarks on phosphorene are necessary. The band gap of phosphorene has been evaluated by different ab initio methods to be about 0.8 or 0.91 eV at the PBE level of theory [35][39], 1.61 eV at the HSE level of theory [35], and 2.0 eV at the GW level of theory [39]. In [8] a value

Deformation-driven catalysis of nanocrystallization in amorphous Al alloys

• Rainer J. Hebert,
• John H. Perepezko,
• Harald Rösner and
• Gerhard Wilde

Beilstein J. Nanotechnol. 2016, 7, 1428–1433, doi:10.3762/bjnano.7.134

• Alexander von Humboldt Stiftung for JHP and the DFG for GW is gratefully acknowledged.

Invariance of molecular charge transport upon changes of extended molecule size and several related issues

• Ioan Bâldea

Beilstein J. Nanotechnol. 2016, 7, 418–431, doi:10.3762/bjnano.7.37

• approaches one should go beyond the DFT level and resort to elaborate many-body schemes [16][39]. These many-body schemes are numerically prohibitive even at the lowest (GW [40]) level. For this reason, to be feasible, calculations cannot avoid treating electrodes within WBL(-type) approximations

Time-dependent growth of crystalline Au⁰-nanoparticles in cyanobacteria as self-reproducing bioreactors: 2. Anabaena cylindrica

• Liz M. Rösken,
• Felix Cappel,
• Susanne Körsten,
• Christian B. Fischer,
• Andreas Schönleber,
• Sander van Smaalen,
• Stefan Geimer,
• Christian Beresko,
• Georg Ankerhold and
• Stefan Wehner

Beilstein J. Nanotechnol. 2016, 7, 312–327, doi:10.3762/bjnano.7.30

• ) and a repetition rate of 80 pulses per second was used. The plasma was generated by focusing the laser pulses on the sample surface by a quartz glass lens with a focal length of 20 mm. An irradiance of 2 GW per cm2 has been achieved. The plasma emission was imaged by a combination of two quartz lenses

Can molecular projected density of states (PDOS) be systematically used in electronic conductance analysis?

• Tonatiuh Rangel,
• Gian-Marco Rignanese and
• Valerio Olevano

Beilstein J. Nanotechnol. 2015, 6, 1247–1259, doi:10.3762/bjnano.6.128

• model [18][19][20][21] or ab initio GW corrections [22][23], arising a yet-to-be solved controversy [24][25][26][27][28][29][30][31][32]. In addition to calculations and measurements, a physical interpretation of the conductance is needed. In the end, a complete picture of the mechanisms governing

Chains of carbon atoms: A vision or a new nanomaterial?

• Florian Banhart

Beilstein J. Nanotechnol. 2015, 6, 559–569, doi:10.3762/bjnano.6.58

• bandgap. Simulations show that a strain of 10% leads to a bandgap of 1.5–3.0 eV, depending on the approximation (DFT, GW) [19][23]. The electrical properties of chains can only be measured by contacts through single atoms. The bonding characteristics at this particular point are of paramount importance

• perturbation theory (MBPT) in the GW approximation including electron–electron interactions resulted in more accurate calculations. Without discussing the applicability and reliability of different computational techniques, a short overview of some predicted properties of carbon chains will be given in this

Thermal stability and reduction of iron oxide nanowires at moderate temperatures

• Annalisa Paolone,
• Marco Angelucci,
• Stefania Panero,
• Maria Grazia Betti and
• Carlo Mariani

Beilstein J. Nanotechnol. 2014, 5, 323–328, doi:10.3762/bjnano.5.36

• associated with multiple oxidation states [30][31][32]. We fit the experimental data with three Voigt (Lorentzian–Gaussian) functions with all peaks having the same Gaussian width (GW = 1.8 eV) and Lorentzian width (LW = 1.0 eV). The lineshape and BE of the Fe 3p core level confirm the Fe3+ oxidation state

Many-body effects in semiconducting single-wall silicon nanotubes

• Wei Wei and
• Timo Jacob

Beilstein J. Nanotechnol. 2014, 5, 19–25, doi:10.3762/bjnano.5.2

• Wei Wei Timo Jacob Institute of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, D-89081 Ulm, Germany 10.3762/bjnano.5.2 Abstract The electronic and optical properties of semiconducting silicon nanotubes (SiNTs) are studied by means of the many-body Green’s function method, i.e., GW

• SiNTs from 0.65, 0.28 and 0.05 eV at DFT level to 1.9, 1.22 and 0.79 eV at GW level. The Coulomb electron−hole (e−h) interactions significantly modify optical absorption properties obtained at noninteracting-particle level with the formation of bound excitons with considerable binding energies (of the

• ; excitons; GW approximation; many body effects; silicon; Introduction Silicon nanotubes [1][2][3][4][5] (SiNTs) have been demonstrated to be emerging materials with exclusive applications in micro- and nanoelectronics [6][7][8][9][10][11][12]. An extra advantage of SiNTs lies in the natural compatibility

Effect of normal load and roughness on the nanoscale friction coefficient in the elastic and plastic contact regime

• Aditya Kumar,
• Thorsten Staedler and
• Xin Jiang

Beilstein J. Nanotechnol. 2013, 4, 66–71, doi:10.3762/bjnano.4.7

• contact and the classical work of Greenwood and Williamson in 1966 (GW model [5][6]) for purely elastic contact. According to the GW model, the establishment of elastic or plastic contact is independent of the applied normal load and only influenced by the physical properties of the contacting bodies. To

• account for elastic–plastic asperity contacts, Chang (CEB model [7][8]) extended the GW model to an elastic–plastic regime assuming the volume conservation law for asperities. However, the CEB model neglects the higher plasticity of the contact in resistance to the additional tangential loading. Later

• different roughness values (fused silica (FS) and diamond-like carbon (DLC)) have been carried out. Aside from the normal load, the tip radius of the conical diamond indenter has been varied in these experiments. The friction coefficients were measured and compared to the GW and the KE model as well as the

Towards quantitative accuracy in first-principles transport calculations: The GW method applied to alkane/gold junctions

• Mikkel Strange and
• Kristian S. Thygesen

Beilstein J. Nanotechnol. 2011, 2, 746–754, doi:10.3762/bjnano.2.82

• -standing problem in the field of charge transport. Here we demonstrate excellent agreement with experiments for the transport properties of the gold/alkanediamine benchmark system when electron–electron interactions are described by the many-body GW approximation. The conductance follows an exponential

• tunneling process comprise states delocalized over the carbon backbone and states localized on the amine end groups. We find that dynamic screening effects renormalize the two types of states in qualitatively different ways when the molecule is inserted in the junction. Consequently, the GW transport

• results cannot be mimicked by DFT calculations employing a simple scissors operator. Keywords: alkanes; density functional theory; electron transport; gold junction; GW; Introduction The conductance of a molecule sandwiched between metallic electrodes is sensitive to the chemical and electronic