In cryptanalysis, security of ciphers vis-a-vis attacks is gauged against three criteria of complexities, i.e., computations, memory and time. Some features may not be so apparent in a particular domain, and their analysis in a transformed domain often reveals interesting patterns. Moreover, the complexity criteria in different domains are different and performance improvements are often achiev...

The DFT can be reduced from exponential time with the Fast Fourier Transform algorithm. Fast Fourier Transform (FFT) One wonders if the DFT can be computed faster: Does another computational procedure an algorithm exist that can compute the same quantity, but more e ciently. We could seek methods that reduce the constant of proportionality, but do not change the DFT's complexity O ( N ) . Here,...

Novel triene merocyanines, i.e. 1-styryleth-2-enylidene and 4-(1,3,3-trimethylindolin-2-ylidene)but-2-en-1-ylideneindolones are obtained in good to excellent yields in a consecutive three-component insertion Sonogashira coupling-addition sequence. The selectivity of either series is remarkable and has its origin in the stepwise character of the terminal addition step as shown by extensive compu...

The formation energies of LiCoO 2 , LiNiO and LiMnO were calculated using a combination adequately selected Hess cycles DFT computations. Several exchange-correlation functionals tested PBE for solids...

Thermodynamic and spectroscopic properties of molecular complexes featuring non-covalent interactions, such as van der Waals forces and hydrogen bonds, are of fundamental interest in many fields, ranging from chemistry and biology to nanotechnology. In the present work the homodimers of difluoromethane (CH2F2) and sulfur dioxide (SO2) are investigated theoretically using dispersion-corrected de...

The conformational stability of “melon”, the most commonly observed graphitic carbon nitride (g-CN), is revisited by DFT computations, evidencing close competition among several polymorphs with distinct photophysical properties.

We demonstrate applications of quantitative structure–property relationship (QSPR) modeling to supplement first-principles computations in materials design. We have here focused on the design of polymers with specific electronic properties. We first show that common materials properties such as the glass transition temperature (Tg) can be effectively modeled by QSPR to generate highly predictiv...

Polynitroxides with varying numbers of nitroxide groups (one to four) derived from different aromatic core structures show intramolecular electron spin-spin coupling. The scope of this study is to establish an easy methodology for extracting structural, dynamical, and thermodynamical information from the EPR spectra of these polynitroxides which might find use as spin probes in complex systems,...

Keto-bromothymol blue [BTB]keto was quantitatively prepared by potassium permanganate oxidation of bromothymol in an alkaline medium at pH > 12. When reacting with dinitrophenyl hydrazine and hydroxylamine, the obtained keto derivatives were characterized FTIR, TDDFT-DFDT computations, optical properties. The resulting compounds found to have a high chelation affinity most hydroxylamine forming...