Density-functional theory (DFT) and its variations provide a fruitful approach to the computational modeling of the microscopic structures and phase behavior of soft-condensed matter. The methodology takes deep root in quantum mechanics but shares a mathematical similarity with a number of classical approaches in statistical mechanics. This review discusses different strategies commonly used to...

The problem of constructing an orthogonal set of eigenvectors for a DFT matrix is well studied. An elegant solution is mentioned by Matveev in [1]. In this paper, we present a distilled form of his solution including some steps unexplained in his paper, along with correction of typos and errors using more consistent notation. Then we compare the computational complexity of his method with the m...

In the quest for a cost-effective level of theory able to describe a large portion of the ground and excited potential energy surfaces of large chromophores, promising approaches are rooted in various approximations to the exact density functional theory (DFT). In the present work, we investigate how generalized Kohn-Sham DFT (GKS-DFT), time-dependent DFT (TDDFT), and spin-restricted ensemble-D...

A D-A-d-type hole transport material (HTM) was chosen for perovskite solar cells (PSCs) based on dicyanofluoranthene core with meta-methoxyl substitutions (BTF6) and different substitutes were introduced onto the fluoranthene of BTF6 instead cyano (CN) groups. The optical emission absorption spectra, reorganization energy, stability, solubility, mobility examined using density functional theory...

We compute the absorption and emission energies and hence Stokes shifts of small diamondoids as a function of size using different theoretical approaches, including density-functional theory (DFT) and quantum Monte Carlo (QMC) calculations. The absorption spectra of these molecules are also investigated by time-dependent DFT and compared with experiment. We analyze the structural distortion and...

Nano carbon materials as nanotube and fullerene have a potential for applications to the advanced industries. For nano carbon materials, it has been recognized that large-scale simulation is a powerful and efficient tool to find and create new functional nano carbon materials. Aiming at conducting the productive simulation for nano-materials, we have developed the large-scale simulation models ...

Classical all-atom molecular dynamics (MD) simulations and quantum mechanical (QM) time-dependent density functional theory (TD-DFT) calculations are employed to study the conformational and photophysical properties of the first emitter excited state of tetramethyl-rhodamine iso-thiocyanate fluorophore in aqueous solution. For this purpose, a specific and accurate force field has been parameter...

theoretical study of the electronic structure, and nonlinear optical properties (nlo) analysis of 12-crown-4were done using density functional theory (dft) evaluations at the b3lyp/6-311g (d,p) level of theory. the optimized structure is nonlinear compound as indicated from the dihedral angles were presented. the calculated ehomo and elumo energies of 12-crown-4 (12cn4) can be used to explain t...

The molecular structure, UV-visible spectra, and optical properties of D-π-A conjugated organic dye molecules (Disperse Red 1 (DR1) Disperse 73 (DR73)) were analyzed using density functional theory (DFT) time-dependent (TD-DFT) compared with azobenzene molecule to study the effect donor acceptor substituents on properties. performance DFT functionals is investigated B3LYP hybrid three long-rang...