The photo-isomerization of o-acetylbenzaldehyde (oABA) in acetonitrile was studied by femto- and nanosecond transient absorption spectroscopy. Spectroscopic signatures are assigned with the aid of TD-DFT, TD-CAM-DFT and DFT-MRCI computations. The isomerization yields a lactone, 3-methylphthalide (3MP), with a quantum yield of 0.3 (30%). As evidenced by femtosecond stimulated Raman spectroscopy ...

The first proton transfer in the bacteriorhodopsin photocycle takes place during the L → M transition. Structural details of the pre proton transfer L intermediate have been investigated using experiments and computations. Here, we assess L-state structural models by performing hybrid quantum mechanical/molecular mechanical molecular dynamics and excitation energy calculations. The computations...

1 Abstract This work introduces a relative diffusion transformation (RDT)-a simple unitary transformation which acts in a subspace, localized by an oracle. Such a transformation can not be fulfilled on quantum Turing machines with this oracle in polynomial time in general case. It is proved, that every function f : ω n −→ ω n , card(ω) = 4, computable in time T (n) and space S(n) on classical 1...

Quantum-chemical processes in liquid environments impact broad areas of science, from molecular biology to geology to electrochemistry. While densityfunctional theory (DFT) has enabled efficient quantum-mechanical calculations which profoundly impact understanding of atomic-scale phenomena, realistic description of the liquid remains a challenge. Here, we present an approach based on joint dens...

In order to better understand the origin of life and the production of artificial living organisms and programmable nano-biorobots we used ab initio quantum mechanical (QM) Hartree-Fock (HF), density functional theory (DFT), QM semiempirical PM3 [1, 2} and molecular dynamics (MD) NAMD, GROMACS and CHARMM simulations [3-5] to investigate various bioorganic systems of artificial minimal living or...

Density Functional Theory is situated within the evolution of Quantum Chemistry as a facilitator of computations and a provider of new, chemical insights. The importance of the latter branch of DFT, conceptual DFT is highlighted following Parr's dictum "to calculate a molecule is not to understand it". An overview is given of the most important reactivity descriptors and the principles they are...

By using quantum mechanical DFT calculations, the most probable structures of the bambus[6]uril.ClO4- and bambus[6]uril.BF4- anionic complex species were derived. In these two complexes having C3 symmetry, each of the considered anions, included in the macrocyclic cavity, is bound by 12 weak hydrogen bonds between methine hydrogen atoms on the convex face of glycoluril units and the respective ...

In this work, we perform a set of quantum mechanical calculations on compounds bromoxynil and its derivatives. Various properties entropy, dipole moment, energy, IR spectra studied by using DFT method in Gaussian calculations. The solubility and inhibition power of these compounds compared with each other. IR frequencies compared with experimental values.

1 Abstract It is proved, that every function F (n) computable in time T (n) and space S(n) on classical 1-dimensional cellular automaton, can be computed with certainty in time O(T 1/2 S) on quantum computer with multipro-cessor. Multiprocessor consists of √ T quantum devices P 1 , P 2 ,. .. , P √ T. They work in parallel-serial mode and interact by classical lows. Each of P i contains O(S(n)) ...

By using quantum mechanical DFT calculations, the most probable structure of the bambus[6]uril x NO3(-) anionic complex species was derived. In this complex having C3 symmetry, the nitrate anion NO3(-), included in the macrocyclic cavity, is bound by twelve weak hydrogen bonds between methine hydrogen atoms on the convex face of glycoluril units and the considered NO3(-) ion.