Photophysical and photochemical dynamics of ground state and excited state proton transfer reaction is reported for Pyrrole 2-Caboxyldehyde (PCL). Steady state absorption and emission measurements are conducted in this five member heterocyclic system (PCL). The theoretical investigation is done by using different quantum mechanical methods (e.g. Hartree Fock, DFT, MP2, CCSD etc.). The reaction ...

We prepared a series of meso-thienyl boron-dipyrromethene (Bodipy) derivatives to investigate the spin–orbit charge transfer intersystem crossing (SOCT-ISC). The photophysical properties compounds were studied by steady-state and femtosecond/nanosecond transient absorption spectroscopy, as well density functional theory (DFT) computations. Different from meso-phenyl Bodipy analogues, are weakly...

The photo tautomerisations of ortho-nitrotoluene (oNT) and its methylated derivative ortho-ethylnitrobenzene (oENB) have been studied by means of femtosecond spectroscopy and (TD)-DFT computations. In UV/Vis transient absorption spectroscopy a band peaking at 400 nm is seen to rise in a bi-modal manner with time constants of 1-10 ps and 1500 ps. Femtosecond stimulated Raman experiments clearly ...

The key step in the reaction mechanism of multicopper oxidases (MCOs)--the cleavage of the O-O bond in O2--has been investigated using combined quantum mechanical and molecular mechanical (QM/MM) methods. This process represents a reaction pathway from the peroxy intermediate after it accepts one electron from the nearby type-1 Cu site to the experimentally-observed native intermediate, which i...

The structural and electronic properties of all-thiophene dendrimers and dendrons in solution have been evaluated using very different theoretical approaches based on quantum mechanical (QM) and hybrid QM/molecular mechanics (MM) methodologies: (i) calculations on minimum energy conformations using an implicit solvation model in combination with density functional theory (DFT) or time-dependent...

The quantum chemistry polarizable force field program (QuanPol) is implemented to perform combined quantum mechanical and molecular mechanical (QM/MM) calculations with induced dipole polarizable force fields and induced surface charge continuum solvation models. The QM methods include Hartree-Fock method, density functional theory method (DFT), generalized valence bond theory method, multiconf...

Data-driven machine learning has emerged to address the limitations of traditional methods when modeling interatomic interactions in materials, such as electronic density functional theory (DFT) and semi-empirical potentials. These machine-learning frameworks involve mathematical models coupled quantum mechanical data. In present article, we focus on moment tensor potential (MTP) framework. Mor...

We carry out a first-principles atomistic study of the electronic mechanisms of ligand binding and discrimination in the myoglobin protein. Electronic correlation effects are taken into account using one of the most advanced methods currently available, namely a linear-scaling density functional theory (DFT) approach wherein the treatment of localized iron 3d electrons is further refined using ...

FOX-7 (1,1-diamino-2,2-dinitroethylene) recently is expected as a relatively new energetic material with high-performance and low sensitivity. The RHF and MP2 levels and DFT method with B3LYP functional with aug-cc-pVDZ basis set have been used for obtaining equilibrium geometry and Rho function (electron density distribution). By the aid of fundamental physical theorems implemented in the ...

It has recently been shown that electronic transport in zigzag graphene nanoribbons becomes spin-polarized upon application of an electric field across the nanoribbon width. However, the electric fields required to experimentally induce this magnetic state are typically large and difficult to apply in practice. Here, using both first-principles density functional theory (DFT) and time-dependent...