Computational Physics

Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT) were treated according to Becke’s three Lee–Yang–Parr (B3LYP) correlation potential due to its less error value than other functionals. This molecule has biological studies are useful for fields, due to its thermal stability and less energy bang gap of probe has luminescence applications.

The molecular geometry, vibrational frequencies of 3-(trifluromethyl) phenyl isothiocyanate in the ground state have been analyzed using density functional theory calculation (B3LYP) with 6-311++G (d,p) and 6-311++G (2d,2p) basis sets. The optimized geometrical parameters obtained by DFT calculations are in good agreement with experimental values. Comparison of the observed fundamental vibrational frequencies of the 3-(trifluromethyl) phenyl isothiocyanate and calculated result by DFT/B3LYP/6-311++G(d,p)/6-311++G (2d,2p) is superior for molecular vibrational problems. A detailed interpretation of the FTIR and FT-Raman spectra of 3-(trifluromethyl) phenyl isothiocyanate are reported on the basis of the calculated potential energy distribution (PED).

In this study a quick summary for the back-hole theory was presented. It was presented earlier in from of graduation project at university of Bahri, college of applied and industrial sciences department of physics, Khartoum, Sudan by the second author and under supervision of the first author. Black holes were once a star shining for years, before eventually collapse on their core forming the BH. There are three cases for a star non stable end is either a white dwarf, a neutron star or a black hole which is completely depend on the mass of the previous star which are called a compact star due to their highly condensation states. In this paper a quick summary for the theory was presented.

Over several years, 5-Nitro 2-Furaldehyde Semicarbozone, otherwise known as Nitrofurazone has been in widespread use as anti-bacterial drug. The recording of FTIR and Laser Raman Spectra is done for the characteristic vibrations of C=N, N-N and furan ring systems and the tentative vibrational assignments have been reported. In the present investigation, vibrational assignments has been carried out for the molecule of the title compound using fundamental modes of vibration observed in Infrared and Raman Spectroscopy. The vibrational modes are classified into a’ and a” irreducible representations. Thus 42 fundamental modes of vibration ie.29a’ and 13a” vibrations are considered. A satisfactory vibrational band assignment has been made by using the FTIR Laser Raman Spectra of the compound.

Normal coordinate calculations of Adenine have been carried out using Wilson’s FG matrix mechanism on the basis of General Valence Force Field (GVFF) for both in-plane and out-of-plane vibrations. The potential energy constants obtained in this study are refined using numerical methods. A satisfactory vibrational band assignment has been made by using FT-IR and FT-Raman spectra of the title compound.

Ultrasonic velocity (U), viscosity (?) and density (?), were measured for liquid mixtures of Brompheniramine and1-pentanol at 303,308 and 313K. Adiabatic compressibility (?), viscous relaxation time (?), free volume (Vf), free length (Lf), and Gibbs free energy (?G) were determined. Excess values of that parameters (?E, LfE , Vf E ,?E and ?GE ) also calculated and elucidated in terms of intermolecular interaction like hydrogen bond between selected liquid system. It was observed that homo and hetero association of molecules decreased with the temperatures.

A theoretical model describing hot-electron injection effects on the high-frequency electrical conductivity of graphene under DC-AC fields is presented. The quasiclassical Boltzmann kinetic equation, within the constant relaxation-time approximation, is employed to obtain the nonequilibrium electron distribution function. An explicit analytical expression for the electrical conductivity at arbitrary injection rates is subsequently derived. A systematic analysis of frequency-dependent electrical conductivity is performed across a range of hot-electron injection rates at a constant DC field. At sufficiently high injection rates, a pronounced peak is observed that is well suited to terahertz radiation generation, with negative differential conductivity (NDC) arising from the DC field and domain formation associated with NDC being suppressed by the AC field. These findings indicate that graphene subjected to hot-electron injection may be utilised in high-frequency nanoelectronic device applications.

Variation is an important mathematical physics method in mathematical physics problem. Many physical problems are always concerned with variation, and they can be solved by extremum of functional. We can obtain physical laws by way of variation calculus, such as the solution of problems of central field and electromagnetic field. By application of calculus of variation, the motion of matter can be unified.

Herbal medications have been found to have the same pharmacological efficacy as pharmaceutical medications. Analysing the bioactive components found in herbal extracts is made easier by preliminary screening. The bioactive components in the methanolic extract of Lagerstroemia reginae were examined, as well as spectral investigations of the substance. The bioactive chemical components included in the active methanol extract were also identified via GC-MS analysis. The outcomes showed that the methanol extracts included a phytol component. The isolated pure Phytol compound is characterized by SEM, EDAX, FTIR, UV, H1NMR, C13NMR and GC-MS. The study came to the conclusion that active phytol compounds found in leaf extracts of Lagerstroemia reginae might be used to create plant-based drugs.

In this article computational study by using DFT on Exalite – 392A is reported. The quantum mechanical analysis of various energies of molecule in ground state was calculated by using DFT technique. The effect of the solvent on optimized geometry, Mulliken charge distribution in ground and excited state were analysed. With the help of computed highest occupied molecular orbital (HOMO) - lowest unoccupied molecular orbital (LUMO) gap of Exalite – 392A in different medium, we can analysed solvation energy, ionization potential, electron affinity, chemical hardness, electron chemical potential, electronegativity and global electrophilic. UV-Vis spectrum was obtained by using TDDFT technique. The total electron density (TED), potential distribution over molecule by electrostatic potential (ESP) positions of molecule were obtained from molecular electrostatic potential (MEP) and frontier molecular orbitals (FMO) simulated. Main objective is to determine their electronic, thermodynamic and spectroscopic parameters on the basis of the DFT quantum chemical studies and also we are studying the effect of solvent and solute-solvent interactions. This molecule is helpful in designing of lasers.