Association of aescin with β- and γ-cyclodextrins studied by DFT calculations and spectroscopic methods

• Ana I. Ramos,
• Pedro D. Vaz,
• Susana S. Braga and
• Artur M. S. Silva

Beilstein J. Nanotechnol. 2017, 8, 348–357, doi:10.3762/bjnano.8.37

• functional theory (DFT) calculations on the interaction of aescin Ib with CDs show that an inclusion can indeed occur and it is further demonstrated that the wider cavity of γ-CD is more adequate to accommodate this large guest. ROESY spectroscopy is consistent with the formation of a complex in which the

• method applied to aqueous-phase 1H nuclear magnetic resonance (1H NMR) has demonstrated that the preferred CD/aescin inclusion stoichiometries are 2:1 with β-CD and 1:1 with γ-CD. The affinity constant calculated for γ-CD·aescin was 894 M−1, while for 2β-CD·aescin it was estimated to be 715 M−1. Density

Colorimetric gas detection by the varying thickness of a thin film of ultrasmall PTSA-coated TiO₂ nanoparticles on a Si substrate

• Urmas Joost,
• Andris Šutka,
• Meeri Visnapuu,
• Aile Tamm,
• Meeri Lembinen,
• Mikk Antsov,
• Kathriin Utt,
• Krisjanis Smits,
• Ergo Nõmmiste and
• Vambola Kisand

Beilstein J. Nanotechnol. 2017, 8, 229–236, doi:10.3762/bjnano.8.25

• in the gas phase was first optimized with Gaussian 09 [22] using the density functional theory (DFT)-based exchange and correlation functional Perdew–Burke–Ernzerhof (PBE) [23][24], and cc-pvtz basis sets [25][26][27][28]. The optimized geometry was then used to calculate the XPS spectra. These were

Tunable plasmons in regular planar arrays of graphene nanoribbons with armchair and zigzag-shaped edges

• Cristian Vacacela Gomez,
• Michele Pisarra,
• Mario Gravina and
• Antonello Sindona

Beilstein J. Nanotechnol. 2017, 8, 172–182, doi:10.3762/bjnano.8.18

• , width and chirality of each GNR, or the in-plane distance between contiguous GNRs. Our study is carried out using time-dependent (TD) density functional theory (DFT), within the random phase approximation (RPA). The computations are performed at room temperature (T = 300 K), including both intrinsic and

Monolayer graphene/SiC Schottky barrier diodes with improved barrier height uniformity as a sensing platform for the detection of heavy metals

• Ivan Shtepliuk,
• Jens Eriksson,
• Volodymyr Khranovskyy,
• Tihomir Iakimov,
• Anita Lloyd Spetz and
• Rositsa Yakimova

Beilstein J. Nanotechnol. 2016, 7, 1800–1814, doi:10.3762/bjnano.7.173

• behaviour and a good quality of ohmic palladium–graphene contacts. Keeping in mind the strong sensitivity of graphene to analytes we propose the possibility to use the graphene/SiC Schottky diode as a sensing platform for the recognition of toxic heavy metals. Using density functional theory (DFT

• Schottky barrier diodes with improved barrier height uniformity, formed on uniform 1 ML graphene. Based on density functional theory (DFT) calculations and experimental findings we propose a strategy for development of a sensing platform for detection of the toxic heavy metals Cd, Hg and Pb. Experimental

Fracture behaviors of pre-cracked monolayer molybdenum disulfide: A molecular dynamics study

• Qi-lin Xiong,
• Zhen-huan Li and
• Xiao-geng Tian

Beilstein J. Nanotechnol. 2016, 7, 1411–1420, doi:10.3762/bjnano.7.132

• the defect-free MoS2 sheets have been investigated by many researchers using different methods. Cooper et al. calculated the nonlinear elastic response of two-dimensional MoS2 with first-principles density functional theory (DFT) method [8]. Castellanos-Gomez et al. [9] performed bending test

Preparation of alginate–chitosan–cyclodextrin micro- and nanoparticles loaded with anti-tuberculosis compounds

• Albert Ivancic,
• Fliur Macaev,
• Fatma Aksakal,
• Veaceslav Boldescu,
• Serghei Pogrebnoi and
• Gheorghe Duca

Beilstein J. Nanotechnol. 2016, 7, 1208–1218, doi:10.3762/bjnano.7.112

• density distribution. It has been detected that alginate–chitosan–cyclodextrin microparticulate systems loaded with INH and ISN are as effective as pure INH applied in higher dosages. Keywords: chitosan; β-cyclodextrin; density functional theory (DFT); isoconazole; isoniazid; molecular docking

• candidates for the development of novel antitubercular agents [28]. In this study, docking of isoconazole into the active site of InhA was carried out to predict the binding affinity and non-covalent interactions between them. Density functional theory (DFT) based calculations were also performed for the

• docking, the geometry of the initial structure of isoconazole was built and optimized by using the Gaussian 09 software [38]. Geometry optimization was performed using density functional theory (DFT) at the B3LYP (Becke, three-parameter, Lee-Yang-Parr)/6-31G (d, p) level [39][40]. For the docking studies

First-principles study of the structure of water layers on flat and stepped Pb electrodes

• Xiaohang Lin,
• Ferdinand Evers and
• Axel Groß

Beilstein J. Nanotechnol. 2016, 7, 533–543, doi:10.3762/bjnano.7.47

• Xiaohang Lin Ferdinand Evers Axel Gross Institut für Theoretische Chemie, Universität Ulm, 89069 Ulm, Germany Institut für Theoretische Physik, Universität Regensburg, 93040 Regensburg, Germany 10.3762/bjnano.7.47 Abstract On the basis of perodic density functional theory (DFT) calculations, we

• , but rather becomes disordered [30][40]. In the present work, we have addressed structural and electronic properties of water layers on flat and stepped Pb surfaces using periodic density functional theory (DFT) calculations. We will show the consequences of the large lattice constant of Pb on the

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

• particularly true in (chemisorption) cases where the anchoring groups form covalent bonds to the electrodes. Within current approaches to molecular charge transport, mostly based on nonequilibrium Keldysh Green’s functions (NEGF) combined with density functional theory (DFT), the molecular device is

Rigid multipodal platforms for metal surfaces

• Michal Valášek,
• Marcin Lindner and
• Marcel Mayor

Beilstein J. Nanotechnol. 2016, 7, 374–405, doi:10.3762/bjnano.7.34

• . Consequently, no further dilution of the molecules is required. The rod-like substituent is almost perpendicular to the plane determined by the three thiols and the head ferrocenyl group is 16 Å above the gold surface, as optimized by density functional theory (DFT) calculations. The extended analysis of the

Surface-site reactivity in small-molecule adsorption: A theoretical study of thiol binding on multi-coordinated gold clusters

• Elvis C. M. Ting,
• Tatiana Popa and
• Irina Paci

Beilstein J. Nanotechnol. 2016, 7, 53–61, doi:10.3762/bjnano.7.6

• central gold atom. On the Au20 cluster, only the 10 gold binding sites on the top layer were studied (labeled a–j in Figure 1c). Density functional theory (DFT) methodology. Calculations were performed using the generalized gradient approximation-based Perdew–Burke–Ernzerhof (PBE) functional [71] with and

Effects of electronic coupling and electrostatic potential on charge transport in carbon-based molecular electronic junctions

• Richard L. McCreery

Beilstein J. Nanotechnol. 2016, 7, 32–46, doi:10.3762/bjnano.7.4

• “compression” of tunneling barriers predicted to range over 2.4 eV based on the free molecule energy levels to an observed range of 1.3 ± 0.2 eV in carbon-based MJs [31][34]. The current report describes the application of density functional theory (DFT) to carbon-based MJs, in order to investigate which

Calculations of helium separation via uniform pores of stanene-based membranes

• Guoping Gao,
• Yan Jiao,
• Yalong Jiao,
• Fengxian Ma,
• Liangzhi Kou and
• Aijun Du

Beilstein J. Nanotechnol. 2015, 6, 2470–2476, doi:10.3762/bjnano.6.256

• . Most interestingly, the 2D Sn-based materials can be further strain-engineered to achieve improved He separation performance by taking both diffusion and selectivity into account. Computational Method Density functional theory (DFT) calculations were carried out using the Vienna ab initio simulation

Negative differential electrical resistance of a rotational organic nanomotor

• Hatef Sadeghi,
• Sara Sangtarash,
• Qusiy Al-Galiby,
• Rachel Sparks,
• Steven Bailey and
• Colin J. Lambert

Beilstein J. Nanotechnol. 2015, 6, 2332–2337, doi:10.3762/bjnano.6.240

• molecule. We use the SIESTA [42] implementation of the density functional theory (DFT) with a van der Waals density functional [43][44] and extended and corrected double-zeta-polarised basis sets of the pseudoatomic orbitals. The geometries were optimised by relaxing the atomic forces to less than 20 meV/Å

Core-level spectra and molecular deformation in adsorption: V-shaped pentacene on Al(001)

• Anu Baby,
• He Lin,
• Gian Paolo Brivio,
• Luca Floreano and
• Guido Fratesi

Beilstein J. Nanotechnol. 2015, 6, 2242–2251, doi:10.3762/bjnano.6.230

• splitting of the sigma resonances measured along the two in-plane molecular axes. Keywords: aluminum; density functional theory (DFT); near-edge X-ray absorption fine structure (NEXAFS); pentacene; X-ray photoelectron spectroscopy (XPS); Introduction Pentacene has been studied extensively as it is a

• experimental investigations, while the previous ab initio theoretical studies [13][14] on this system were missing long-range van der Waals (vdW) corrections. Simeoni and Picozzi reported a numerical investigation of pentacene on Al(001) by density functional theory (DFT) with the local density approximation

Selective porous gates made from colloidal silica nanoparticles

• Roberto Nisticò,
• Paola Avetta,
• Paola Calza,
• Debora Fabbri,
• Giuliana Magnacca and
• Dominique Scalarone

Beilstein J. Nanotechnol. 2015, 6, 2105–2112, doi:10.3762/bjnano.6.215

• functional theory (DFT) model for slit pores with low regularization was applied on the adsorption branch of the isotherm in order to examine simultaneously both micro- and mesoporosity of samples. The analyses were performed on powdery samples (ca. 100 mg) outgassed for several hours at 300 °C in vacuo

• for secondary electrons collection and EDS probe for elemental analyses. N2 adsorption-desorption experiments were carried out by means of ASAP 2020 instrument (Micromeritics) in order to determine specific surface area (BET model) [44] and porosity (DFT method) [27][45] of samples. The density

Controlled switching of single-molecule junctions by mechanical motion of a phenyl ring

• Yuya Kitaguchi,
• Satoru Habuka,
• Hiroshi Okuyama,
• Shinichiro Hatta,
• Tetsuya Aruga,
• Thomas Frederiksen,
• Magnus Paulsson and
• Hiromu Ueba

Beilstein J. Nanotechnol. 2015, 6, 2088–2095, doi:10.3762/bjnano.6.213

• and can successfully lift up the molecules. The computational approach was detailed in [12]. Briefly, we used Kohn–Sham density functional theory (DFT) implemented in VASP [15][16] to obtain the atomic structure and total energy using the optPBE-vdW [17] exchange-correlation functional. Electron

Large-voltage behavior of charge transport characteristics in nanosystems with weak electron–vibration coupling

• Tomáš Novotný and
• Wolfgang Belzig

Beilstein J. Nanotechnol. 2015, 6, 1853–1859, doi:10.3762/bjnano.6.188

• IETS signals usually proceeds via combination of ab initio structural density functional theory (DFT) calculations determining the parameters of an effective electron–vibrational Hamiltonian with the non-equilibrium Green’s functions (NEGF) evaluation of the IETS features [10]. It had turned out that

Atomic scale interface design and characterisation

• Carla Bittencourt,
• Chris Ewels and
• Arkady V. Krasheninnikov

Beilstein J. Nanotechnol. 2015, 6, 1708–1711, doi:10.3762/bjnano.6.174

• density-functional theory (DFT) approaches. In addition, using DFT-based molecular dynamics, the manipulation of nanostructures by SPM tools and the changes made to the system by the characterization tools, e.g., the production of defects under electron irradiation and their evolution over time, can be

Simple and efficient way of speeding up transmission calculations with k-point sampling

• Jesper Toft Falkenberg and
• Mads Brandbyge

Beilstein J. Nanotechnol. 2015, 6, 1603–1608, doi:10.3762/bjnano.6.164

• -processing; shortest-path; Introduction Calculations of electronic conductance based on first principle methods such as density functional theory (DFT) provide a valuable tool in order to gain insights into electronic transport in nano-conductors and comparison to experiments without employing fitting

Electrical properties and mechanical stability of anchoring groups for single-molecule electronics

• Riccardo Frisenda,
• Simge Tarkuç,
• Elena Galán,
• Mickael L. Perrin,
• Rienk Eelkema,
• Ferdinand C. Grozema and
• Herre S. J. van der Zant

Beilstein J. Nanotechnol. 2015, 6, 1558–1567, doi:10.3762/bjnano.6.159

• of such conductance-time breaking traces. Theoretical calculations. Electronic ground state properties are calculated using density functional theory (DFT) as implemented in the ADF package [38][39], using the GGA-PBE functional [40], and the triple-ζ plus polarization (TZP) basis set. The zeroth

Electron and heat transport in porphyrin-based single-molecule transistors with electro-burnt graphene electrodes

• Hatef Sadeghi,
• Sara Sangtarash and
• Colin J. Lambert

Beilstein J. Nanotechnol. 2015, 6, 1413–1420, doi:10.3762/bjnano.6.146

• interactions. The central porphyrin is also connected to two side groups, which stabilize the molecule within the junction. We first use density functional theory (DFT) to study the electronic structure of the PM. To characterize the gas phase molecule, the isolated PM shown in Figure 1a is relaxed to reach

• junction. Computational Methods The Hamiltonian of the structures described in this paper were obtained using density functional theory (DFT) as described below or constructed from a simple tight-binding model (TB), as shown in Figure 6a. The single orbital per atom of site energies are εC = −4.05, εH

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

• established frameworks [5][6] like the Kubo–Greenwood [7][8] or the Landauer [9] formalisms, or the non-equilibrium Green’s function theory [10][11][12]. In the last two decades, the combination of these formalisms with density functional theory (DFT) or many-body perturbation (MBPT) theory allowed for the

Electronic interaction in composites of a conjugated polymer and carbon nanotubes: first-principles calculation and photophysical approaches

• Florian Massuyeau,
• Jany Wéry,
• Jean-Luc Duvail,
• Serge Lefrant,
• Abu Yaya,
• Chris Ewels and
• Eric Faulques

Beilstein J. Nanotechnol. 2015, 6, 1138–1144, doi:10.3762/bjnano.6.115

• density functional theory (DFT) calculations of coupling effects between the polymer and both species of SWNTs. Combined experimental results and first-principles calculations provide evidence that significant electronic interaction can take place between PPV chains and semiconducting SWNTs while metallic

Electrocatalysis on the nm scale

• R. Jürgen Behm

Beilstein J. Nanotechnol. 2015, 6, 1008–1009, doi:10.3762/bjnano.6.103

• developed to a stage where a reliable description of complex surface structures and surface processes (at the solid–gas interface) is possible based on first-principles electronic structure theory (in particular, (periodic) density functional theory (DFT)), but it is also increasingly developing new

Graphene on SiC(0001) inspected by dynamic atomic force microscopy at room temperature

• Mykola Telychko,
• Jan Berger,
• Zsolt Majzik,
• Pavel Jelínek and
• Martin Švec

Beilstein J. Nanotechnol. 2015, 6, 901–906, doi:10.3762/bjnano.6.93

• sample. KPFM parabola was measured by sweeping the bias voltage and measuring the Δf value [24]. In order to estimate the SLG corrugation we carried out large scale total energy density functional theory (DFT) calculations. We used local-orbital FIREBALL code [25][26]. FIREBALL uses an optimized [27