Excitation energies, oscillator strengths, and vacuum-ultraviolet/deep-ultraviolet absorption spectra were calculated for nerve agents, such as sarin, soman, VX, tabun, mustard gas, and analogs. We used time-dependent density functional theory (TD-DFT) methods that included B3LYP combined with basis sets of cc-pVDZ and cc-pVTZ, and ωB97XD with cc-pVTZ. The vertical ionization energies were also...

Semiconductor-based gas sensors are of great interest in both industrial and research settings, but poor selectivity has hindered their further development. Current efforts including doping, surface modifications facet controlling have been proved effective. However, the “methods-selectivity” correlation is ambiguous because uncontrollable defects states during experiments. Here, as a case stud...

A major application of the FFT is fast convolution or fast ltering where the DFT of the signal is multiplied term-by-term by the DFT of the impulse (helps to be doing nite impulse response (FIR) ltering) and the time-domain output is obtained by taking the inverse DFT of that product. What is less well-known is the DFT can be calculated by convolution. There are several di erent approaches to t...

The importance of organic electrochromic materials has grown considerably in recent decades due to their application in smart window, automotive, and aircraft technologies. Theoretical prediction of the optical properties should contribute to their better characterization and help the explanation of the experimental data. By using various exchange-correlation functionals, we show how density fu...

In order to explain the reduced photodynamic (PDT) activity of a recently proposed m-tetra (hydroxyphenyl) porphycene derivative (temocene or THPPo) in terms of singlet oxygen quantum yields compared to porphyrin analogue Foscan (m-THPC), a time dependent DFT investigation has been carried out. Computed electronic transitions, singlet-triplet energy gaps and spin-orbit coupling matrix elements ...

The assessment of defibrillation (DFT) efficacy has long been the standard of care during defibrillator implantation. To ensure an acceptable DFT safety margin, early defibrillator systems frequently required that the shock polarity and the location, type, or number of electrodes had to be altered. Advances in defibrillator and lead technology have resulted in lower and more consistent DFT thre...

highly crystalline and pure lithium metasilicate (li2sio3) and lithium disilicate (li2si2o5) nanomaterials were synthesized by hydrothermal method and characterized by pxrd technique. the changes in the morphology and particle size of the synthesized nanomaterials with reaction time were investigated using sem technique. the uv-vis and photoluminescence spectra of the compounds were studied. th...

We report the implementation and application of linear response density-functional theory (DFT) based on the 4-component relativistic Dirac–Coulomb Hamiltonian. The theory is cast in the language of second quantization and is based on the quasienergy formalism (Floquet theory), replacing the initial state dependence of the Runge–Gross theorem by periodic boundary conditions. Contradictions in c...

If robust spectroscopic techniques are to be developed for the detection and identification of pathogens, one must understand the relevant spectroscopic properties of the target molecules. In this paper, we employ density functional theory (DFT) to study the structural, electronic, vibrational, optical, and magnetic properties of dipicolinic acid (DPA) and its dianion DPA . Our full geometrical...