The Empirical Tight Binding (ETB) method is widely used in atomistic device simulations. The reliability of such simulations depends very strongly on the choice of basis sets and the ETB parameters. The traditional way of obtaining the ETB parameters is by fitting to experiment data, or critical theoretical bandedges and symmetries rather than a foundational mapping. A further shortcoming of tr...

In this study, we theoretically investigated Methyl hydrazinecarbodithioate by quantum chemical calculations for geometry optimization, vibration frequencies, and electronic structure parameters. The geometry optimization by DFT, ab initio MP2 method and the frequency calculation by DFT method was performed at the highest available Pople style 6-311G++(3df,3pd) basis set level. The semi-emp...

In the present investigation, the results of extensive benchmarking study of density functional theory (DFT) methods on some catalytically important metal dimers have been reported. The calculations were carried out on Al2, Ti2, V2, Cr2, Mn2, Fe2, Co2, Ni2, Cu2, and Zn2 using DFT functionals such as GGA, meta GGA, hybrid meta GGA along with recently developed Minnesota functionals. The bond len...

High-throughput calculations based on density functional theory (DFT) methods have been widely implemented in the scientific community. However, depending on both the properties of interest as well as particular chemical/structural phase space, accuracy even for correct trends remains a key challenge for DFT. In this work, we evaluate the use of quantum Monte Carlo (QMC) to calculate material f...

First-principles quantum-mechanical electronic structure calculations based on the density-functional theory (DFT) is an important ingredient of material sciences. The system sizes handled in usual DFT calculations are limited within a thousand of atoms due to the computational complexity of fully quantummechanical approaches. Real-space DFT (RSDFT) code, which has been developed in our group, ...

in this work, the optimization calculations were carried out on quetiapine hemifumarat, 4, and its analogues, 1-5. these calculations were carried out using the b3lyp/6-31g(d) level of theory. the dft calculations clarified a boat structure for dibenzothiazepine moiety of the molecule which piperazine moiety has a chair conformation. thermal energies (e), enthalpies (h), and free energies (g) o...

Large scale Density Functional Theory (DFT) based electronic structure calculations are highly time consuming and scale poorly with system size. While semi-empirical approximations to DFT result in a reduction in computational time versus ab initio DFT, creating such approximations involves significant manual intervention and is highly inefficient for high-throughput electronic structure screen...

A gold(I) complex with a triphenylphosphine and a monodentate N,N-dimethyldithiocarbamate ligand was synthesized and characterized by Raman spectroscopy and single crystal X-ray diffraction. DFT calculations (Gaussian 09, PBE1PBE/Lanl2dz) were undertaken for a single complex in the gas-phase. The DFT-optimized structure is in good agreement with the crystal structure and the DFT-calculated Rama...

A short introduction to periodic bandstructure methods suitable for the calculation of Mössbauer parameters is presented. These methods are based on density functional theory (because we want to treat big and complicated systems) and must be accurate not only in the bonding region (like pseudopotential approaches), but also near the atomic nuclei since Mössbauer parameters depend crucially on t...

compound (n,n-bis (salicylidene) 1,2-diaminophenylene) was prepared by condensation of ethanolsolution of 2-hydroxybanzaldehyde and 1,2-diaminophenylene. the compound was characterized by1h nmr, infrared spectroscopy (ft-ir) data and analytical data. the geometrical parameters andenergies have been obtained from density functional theory (dft) b3lyp method and hartree-fock (hf) method with 3-21...