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Application Of Computational Methods To The Rational Design Of Photoactive Materials For Solar Cells
Published in Tanmoy Chakraborty, Prabhat Ranjan, Anand Pandey, Computational Chemistry Methodology in Structural Biology and Materials Sciences, 2017
In this case study, a continuum solvation method known as conductor-like polarizable continuum model (CPCM) [23] is employed to simulate the UV-Vis spectra in solutions. In order to make comparisons with the experimental UV-Vis spectrum of the reference TA-St-CA dye, which was measured in ethanol solution [17], the present study has simulated the UV-Vis spectra in ethanol solution. The theoretical UV-Vis spectra of the dyes are calculated using singlet-singlet transitions up to the 30th lowest spin-allowed excited state of each dye. These lowest-energy electronic transitions are then transformed into simulated UV-Vis spectra by GaussView 5 visualization software [24], using a Gaussian broadening function with the full width at half-widths maximum (FWHM) of 2500 cm−1.
2 Reduction with Aluminum to Produce Formic Acid
Published in Fangming Jin, Hydrothermal Reduction of Carbon Dioxide to Low- Carbon Fuels, 2017
Binbin Jin, Guodong Yao, Fangming Jin, Heng Zhong
The strategy consists of a series of ab initio and DFT quantum chemical calculations for the reaction. All the structures at equilibrium and transition states were optimized by a B3LYP functional using the extended 6-311 + G(3df,2p) basis set. To take the solvation effect into account, the polarizable continuum model was applied. The transition state was calculated by following minimum energy paths of the reactions with the use of the Gonzalez–Schlegel intrinsic reaction coordinate algorithm. All calculations were performed using Gaussian 09 [24].
Li -Ion Battery Materials and Electrolytes
Published in Aneeya Kumar Samantara, Satyajit Ratha, Electrochemical Energy Conversion and Storage Systems for Future Sustainability, 2020
In the quantum chemical simulations, the electrolytic solvents are represented by the two solvation models; implicit solvent model and explicit solvent model (Bryantsev, 2012; Marenich et al., 2009; Rayne et al., 2010). The basis of the implicit continuum model is the sharp boundary between the solute and the bulk of the solvent, represented as a structure-less polarizable medium, characterized by its dielectric constant (Tomasi et al., 2005). In these models, the molecule/cluster under investigation is located inside a cavity surrounded by a homogeneous dielectric medium of the solvents such as; acetonitrile (MeCN, ε = 35.6), EC (ε = 89.6), propylene carbonate (PC, ε = 64.0), Diethylene carbonate (DEC, ε = 2.40), DMC (ε = 7.15) and Triethylene glycol dimethyl ether (Triglime, ε = 7.94). The implicit solvent model has been successfully applied in the investigation of the chemical reaction within the surrounding medium (Kushwaha et al., 2017, 2018; Kushwaha and Nayak, 2017), There are several continuum models has proposed for expressing the solvent media, out of which polarizable continuum model (PCM) is generally used to represent continuum dielectric medium. Mathematically, the PCM is expressed by the Poisson-Boltzmann equation which is an expansion term of Poisson’s equation. Recently solvation model on density (SMD) is getting much attention for solvation model (Marenich et al., 2009). Similar to the PCM, the SMD model solve the Poisson-Boltzmann equation analytically, only difference is that SMD model used specific parameterize radii for the construction of cavity. The conductor boundary condition based COSMO solvation model is also an implicit solvent model (Klamt and Schüürmann, 1993). The computational cost calculation using the implicit model is lower in comparison to others while is does not maintain the high accuracy especially reaction mechanism. In the explicit solvation model, the molecular solvents form the solvation shell (changes during transfer between the electrodes) around the Li+ ion, either in the electrolyte or at the electrode interfaces. For example, in the case of EC, the coordination number of Li+ has been found to be four, which reduces at the interfaces (Bhatt et al., 2012; Bhatt and O’Dwyer, 2014; Cui et al., 2016). The explicit solvent model provides the more realistic picture of the solute-solvent interaction in comparison to implicit solvent model. Although the computational cost is the major drawback of the explicit solvent model.
Synthesis of oxidovanadium complexes containing coumarin and naphthalene: bromoperoxidase activity and DNA/BSA binding
Published in Journal of Coordination Chemistry, 2023
Mitali Majumder, Tapashi Das, Kajal Krishna Rajak
The geometries of 1 and 2 were optimized and harmonic frequencies were computed with Gaussian 09 software by the DFT [22] method with B3LYP exchange correlation functional approach [23]. The geometries were fully optimized in solution phase without any symmetry constraints. There was good agreement between the theoretical and experimental structures. On the basis of the optimized ground state geometry, the absorption properties in dichloromethane (DCM) and methanol (MeOH) were calculated by time-dependent density functional theory (TDDFT) [24] related with the conductor-like polarizable continuum model (CPCM) [25]. We computed the lowest 50 singlet-singlet transitions and results of the TD calculations were qualitatively very similar. The TDDFT approach had been established for calculating spectral properties of many transition metal complexes [26]. Due to electronic correlation in the TDDFT (B3LYP) method it can yield accurate electronic excitation energies. Hence TDDFT provides a logical spectral feature for our investigation. In the calculation, the quasi-relativistic pseudo potentials of V ions were anticipated by Hay and Wadt [27] with five valence electrons (outer-core [(4s24p0)] and the (3d3) valence electrons, and a “double-ξ” quality basis set LANL2DZ was adopted as the basis set for V. For H we used 6-31(g) basis set and the 6-31+ G (d, p) basis set for C, N, O atoms for optimization of the ground state geometries. Figures showing MOs and the difference density plots were prepared by using the Gauss View 5.1 software. All the calculations were performed with the Gaussian 09 W software package [28].
Investigation of Aviation Lubricant Aging under Engine Representative Conditions
Published in Tribology Transactions, 2021
Abdolkarim Sheikhansari, Ehsan Alborzi, Christopher Parks, Spiridon Siouris, Simon Blakey
All calculations were performed using Gaussian 09, revision D.01 (20). The calculations used the B3LYP functional (Becke’s three-parameter exchange functional with the correlation function of Lee, Yang, and Parr) (21–23). The cc-pVDZ (correlation-consistent polarized, valence-only, double zeta) basis set (24) was used for all elements. In all calculations, the solvent was accounted for using the polarizable continuum model method as implemented in Gaussian. The solvent parameters for dodecane were used for all calculations (25).
Rutheniumethynyl-triarylamine mixed-valence conjugated system: syntheses, (spectro-)electrochemistry, and theoretical calculations
Published in Journal of Coordination Chemistry, 2019
YA-Ping Ou, Yuxuan Hu, Meng Xu, Aihui Wang, Sheng Hua Liu
Density functional theory (DFT) calculations were performed using the Gaussian09 software [47] at the B3LYP/6-31G* [48] levels of theory. The basis set employed was 6-31G* (Lanl2DZ for Ru atom). Geometry optimization was performed without any symmetry constraints. Electronic transitions were calculated by the time-dependent DFT (TD-DFT) method. The solvation effects in dichloromethane are included for part of the calculations with the conductor-like polarizable continuum model (CPCM) [49, 50].