The electronic structure and spectra of 3-formylchromone and some of its derivatives are investigated using TD-DFT/B3LYB/6-311G (d, p) level of theory. The results of calculations show that all the studied compounds 1–6 are planar, as indicated from the dihedral angles. The electronic absorption spectra of the studied compounds are recorded in the UV-Vis region, in both ethanol (as polar solven...

The electronic structure, Non-Linear Optical (NLO) properties and Natural Bonding Orbital (NBO) analysis of 1,4-dioxane were investigated using the theoretical study of Density Functional Theory (DFT) calculations at the B3LYP/6-311G (d,p) level of theory. The optimized structure is nonlinear as indicated from the dihedral angles.  Natural bonding orbital analysis has been analyzed in terms...

The technique of muon spin rotation ({\mu}SR) has emerged in the last few decades as one most powerful methods obtaining local magnetic information. To make fully quantitative, it is necessary to have an accurate estimate where inside crystal structure implants. This can be provided by density functional theory calculations using approach that termed DFT+{\mu}, with implanted included. article ...

A density functional theory (DFT) is presented for describing the distributions of small ions around an isolated infinitely long polyanionic DNA molecule in the framework of the restricted primitive model. The hard-sphere contribution to the excess Helmholtz energy functional is derived from the modified fundamental measure theory, and the electrostatic interaction is evaluated through a quadra...

In this work, we report results of calculations based on the density functional theory of different species metal-ozone, containing mercury, silver and gold. The chosen species range from small molecules and large transition-metal containing ozone with mercury, silver and gold complexes. A comparative analysis of the description of the metal-oxygen bond obtained by different methodologies is pr...

The density functional theory (DFT) foundations date from the 1920s with the work of Thomas and Fermi, but it was after the work of Hohenberg, Kohn, and Sham in the 1960s, and particularly with the appearance of the B3LYP functional in the early 1990s, that the widespread application of DFT has become a reality. DFT is less computationally demanding than other computational methods with a simil...

A [3+2] cycloaddition (32CA) reaction among a thiocarbonyl ylide (TCY 2) with (E)-4,4,4-trifluoro-4-phenylbut-3-en-2-one (TFB 4) as an electron-deficient enone in tetrahydrofuran (THF) were studied within the Molecular Electron Density Theory (MEDT), at the DFT-B3LYP/6-31G(d) computational level to analysis energetics, selectivities, and mechanistic aspects. The reaction can progress in four co...

We have investigated photosensitizing properties for porphrazine and eleven of its related derivatives based on time-dependent density functional theory (TD-DFT) calculations. The modles have been divided into two categories based on the existence of CN functional group in one category but not in the other one. The other functional groups include H, CH3, F, CF3, C6H5, and C6F5 counterparts. The...

We survey approaches to nonrelativistic density functional theory (DFT) for nuclei using progress toward ab initio DFT for Coulomb systems as a guide. Ab initio DFT starts with a microscopic Hamiltonian and is naturally formulated using orbital-based functionals, which generalize the conventional local-density-plus-gradients form. The orbitals satisfy single-particle equations with multiplicati...

Projection-based embedding provides a simple and numerically robust framework for multiscale wavefunction-in-density-functional-theory (WF-in-DFT) calculations. The approach works well when the approximate DFT is sufficiently accurate to describe the energetics of the low-level subsystem and the coupling between subsystems. It is also necessary that the low-level DFT produces a qualitatively re...