Ultrafast Internal Conversion of Aromatic Molecules Studied
... The quantum mechanical equation of motions of the nuclei and electrons is not exactly solvable, so Born and Oppenheimer approximated the rigorous equation by separating it into the sets of equations of the nuclei and the electrons [1]. Based on the Born-Oppenheimer approximation, a chemical reaction ...
... The quantum mechanical equation of motions of the nuclei and electrons is not exactly solvable, so Born and Oppenheimer approximated the rigorous equation by separating it into the sets of equations of the nuclei and the electrons [1]. Based on the Born-Oppenheimer approximation, a chemical reaction ...
CHAPTER 1 Barrier crossings: classical theory of rare but impor
... For a polypeptide of modest length, the folding time could be, for example, 10−6 s. At comfortable viewing speeds, it takes about one minute of film to record 1 ps of molecular dynamics. Therefore, to capture just one entire folding event, an unedited film would run for several years. To normal view ...
... For a polypeptide of modest length, the folding time could be, for example, 10−6 s. At comfortable viewing speeds, it takes about one minute of film to record 1 ps of molecular dynamics. Therefore, to capture just one entire folding event, an unedited film would run for several years. To normal view ...
Dynamics of molecule-surface interactions from first
... of molecular adsorption and desorption from metal and semiconductor surfaces based on potential energy surfaces that were derived from first-principles electronic structure calculations. In many cases these dynamical simulations are in quantitative agreement with available experiments. Still it is t ...
... of molecular adsorption and desorption from metal and semiconductor surfaces based on potential energy surfaces that were derived from first-principles electronic structure calculations. In many cases these dynamical simulations are in quantitative agreement with available experiments. Still it is t ...
Pressure-controlled motion of single polymers through solid
... pore, they repel each other such that one or both are always likely to be displaced from the pore axis. In the case where the pressure- and voltage-derived forces are well balanced, the net force on the two strands may thus be less than that on a single strand. This slows translocation of folded mol ...
... pore, they repel each other such that one or both are always likely to be displaced from the pore axis. In the case where the pressure- and voltage-derived forces are well balanced, the net force on the two strands may thus be less than that on a single strand. This slows translocation of folded mol ...
STEREOCHEMISTRY - M E S KVM College Valanchery.
... In allenes, the central carbon is sp hybridized. The remaining two p orbitals are perpendicular to each other and each p orbital overlaps with the p orbital of one adjacent carbon atom. Thus the two groups at one end of the allene lie in plane perpendicular to the plane containing the two groups at ...
... In allenes, the central carbon is sp hybridized. The remaining two p orbitals are perpendicular to each other and each p orbital overlaps with the p orbital of one adjacent carbon atom. Thus the two groups at one end of the allene lie in plane perpendicular to the plane containing the two groups at ...
Molecular Orbital
... bonding molecular orbital contribute one net bond and that two electrons in an antibonding molecular orbital cancel the effect of one bond. We can calculate the bond order in the O2 molecule by noting that there are eight valence electrons in bonding molecular orbitals and four valence electrons in ...
... bonding molecular orbital contribute one net bond and that two electrons in an antibonding molecular orbital cancel the effect of one bond. We can calculate the bond order in the O2 molecule by noting that there are eight valence electrons in bonding molecular orbitals and four valence electrons in ...
He–ThO(1Σ+) Interactions at Low Temperatures: Elastic and
... We present an ab initio study of cold 4 He + ThO(1 + ) collisions based on an accurate potential energy surface (PES) evaluated by the coupled cluster method with single, double, and noniterative triple excitations using an extended basis set augmented by bond functions. Variational calculations o ...
... We present an ab initio study of cold 4 He + ThO(1 + ) collisions based on an accurate potential energy surface (PES) evaluated by the coupled cluster method with single, double, and noniterative triple excitations using an extended basis set augmented by bond functions. Variational calculations o ...
High Rydberg states of DABCO: Spectroscopy, ionization potential
... energy for principle quantum number n, R dabco is the reduced-mass corrected Rydberg constant ~109 736.777 cm21!, and d is the quantum defect. Table I lists the observed energy positions with their uncertainties plus the deviation of each line from the calculated value. The energy positions were det ...
... energy for principle quantum number n, R dabco is the reduced-mass corrected Rydberg constant ~109 736.777 cm21!, and d is the quantum defect. Table I lists the observed energy positions with their uncertainties plus the deviation of each line from the calculated value. The energy positions were det ...
Ultrafast electronic dynamics in polyatomic molecules studied using
... the separation of single-order radiation from a comb-like structure of odd-order harmonics (or an extremely broad continuum), because multilayer mirrors with high reflectivity are only available for limited wavelength regions such as 6–7, 13.5 or 30 nm. New techniques such as the timedelay-compensat ...
... the separation of single-order radiation from a comb-like structure of odd-order harmonics (or an extremely broad continuum), because multilayer mirrors with high reflectivity are only available for limited wavelength regions such as 6–7, 13.5 or 30 nm. New techniques such as the timedelay-compensat ...
Order Parameters P2 , P4 , and P6 of Aligned Nematic Liquid
... determination of order parameter, one needs to know angle χ, or should choose dyes with χ close to zero, and (ii) only ⟨P2⟩ can be determined. EPR spectroscopy (spin probe and spin label method) is rather widely used for study of dynamics and orientational order in liquid crystals.20−22,25−28 At pre ...
... determination of order parameter, one needs to know angle χ, or should choose dyes with χ close to zero, and (ii) only ⟨P2⟩ can be determined. EPR spectroscopy (spin probe and spin label method) is rather widely used for study of dynamics and orientational order in liquid crystals.20−22,25−28 At pre ...
File
... Electronegativity and intermediate bonding Electronegativity is defined as follows Electronegativity is the ability of an atom within a covalent bond to attract the bonding pair of electrons. Electronegativity is measured on the Pauling scale (ranges from 0 to 4 F, O, N and Cl are the most electrone ...
... Electronegativity and intermediate bonding Electronegativity is defined as follows Electronegativity is the ability of an atom within a covalent bond to attract the bonding pair of electrons. Electronegativity is measured on the Pauling scale (ranges from 0 to 4 F, O, N and Cl are the most electrone ...
Rotational spectroscopy
Rotational spectroscopy is concerned with the measurement of the energies of transitions between quantized rotational states of molecules in the gas phase. The spectra of polar molecules can be measured in absorption or emission by microwave spectroscopy or by far infrared spectroscopy. The rotational spectra of non-polar molecules cannot be observed by those methods, but can be observed and measured by Raman spectroscopy. Rotational spectroscopy is sometimes referred to as pure rotational spectroscopy to distinguish it from rotational-vibrational spectroscopy where changes in rotational energy occur together with changes in vibrational energy, and also from ro-vibronic spectroscopy (or just vibronic spectroscopy) where rotational, vibrational and electronic energy changes occur simultaneously.For rotational spectroscopy, molecules are classified according to symmetry into spherical top, linear and symmetric top; analytical expressions can be derived for the rotational energy terms of these molecules. Analytical expressions can be derived for the fourth category, asymmetric top, for rotational levels up to J=3, but higher energy levels need to be determined using numerical methods. The rotational energies are derived theoretically by considering the molecules to be rigid rotors and then applying extra terms to account for centrifugal distortion, fine structure, hyperfine structure and Coriolis coupling. Fitting the spectra to the theoretical expressions gives numerical values of the angular moments of inertia from which very precise values of molecular bond lengths and angles can be derived in favorable cases. In the presence of an electrostatic field there is Stark splitting which allows molecular electric dipole moments to be determined.An important application of rotational spectroscopy is in exploration of the chemical composition of the interstellar medium using radio telescopes.