Vector Correlations and Product Rotational Alignments of Reactions Ca+RBr→CaBr+R(R=CH_(3),C_(2) H_(5) and n-C_(3) H_(7))

The quasiclassical trajectory method is used to study the vector correlations of the reactions Ca＋RBr （R=CH3, C2H5 and n-C3H7Br） and the rotational alignment of product CaBr. The product rotational alignment parameters at different collision energies and the vector correlations between the reagent and product are numerically calculated. The vector correlations are described by using the angle distribution functions P（θr）, P（φr）, P（θr, φr） and the polarization-dependent differential cross sections （PDDCSs）. The peak values of P（θr） of the product CaBr from Ca＋CH3Br are larger than those from Ca＋C2H5Br and Ca＋n-C3H7Br. The peak of P（θr） at φr= 3π/2 is apparently stronger than that at φr= x/2 for the three reactions Ca＋RBr. The calculation results show that the rotational angular momentum of the product CaBr is not only aligned, but also oriented along the direction which is perpendicular to the scattering plane.The product CaBr molecules are strongly scattered forward. The orientation and alignment of the product angular momentum will affect the scattering direction of the product molecules to varying degrees.

QSAR of Estrogen of Bisphenol A with 3D Vector of Atomic Property Correlation

Considering atomic property vector and atomic correlative function, the 3-dimensional structural vector of atomic property correlation （3D-VAPC）, a novel descriptor,is defined to characterize a 3-dimensional molecular structure by introducing self-adaptability regulation mechanism and the idea of orientating to customers. Characterizing the structures of 25 bisphenol A compounds by this vector, the QSAR models of three kinds of estrogen activities （ER affinities, gene induction and cell proliferation） have high multiple correlation coefficient （Rcum^2=0.933, 0.813, 0.959） and cross verification coefficient （Qcum^2=0.847, 0.953, 0.798） by support vector machine （SVM）, which suits for nonlinear circumstances. The above results show that the models successfully express the correlation between structure and three kinds of estrogen activities. Therefore, 3D-VAPC exactly reflects the molecular structural information and SVM method correctly describes the correlation between information and property of the compounds.

Vector correlations study of the reaction N(~2D) + H_2(X^1Σ_g^+) →NH(a^1?) + H(~2S) with different collision energies and reagent vibration excitations

Vector correlations of the reaction N（2D） ＋H2（X1∑g＋） NH（a1△）→ ＋ H（2S） are studied based on a recent DMBE- SEC PES for the first excited state ofNH2 [J. Phys. Chem. A 114 9644 （2010）] by using a quasi-classical trajectory method. The effects of collision energy and the reagent initial vibrational excitation on cross section and product polarization are investigated for v = 0-5 and j = 0 states in a wide collision energy range （10-50 kcal/mol）. The integral cross section could be increased by H2 vibration excitation remarkably based on the DMBE-SEC PES. The different phenomena of differential cross sections with different collision energies and reagent vibration excitations are explained. Particularly, the NH molecules are scattered mainly in the backward hemisphere at low vibration quantum number and evolve from backward to forward direction with increasing vibration quantum number, which could be explained by the fact that the vibrational excitation enlarges the H-H distance in the entrance channel, thus enhancing the probability of collision between N atom and H atom. A further study on product polarization demonstrates that the collision energy and vibrational excitation of the reagent remarkably influence the distributions of P（Or）, P（（Pr）, and P（Or, （Pr）.

Validation of the Model Obtained Ice Drift Fields Based on Satellite Derived Data Using a Vector Correlation Indexes in an Invariant Form

The article considers results of validation of a sea ice modeling data using a novel methodology on the vector algebra theoretical bases. The vectorial-algebraic approach developed and was in use in Russia for an analysis of time series of vector values--wind, currents ice drift etc. The vectorial-algebraic approach allows significantly compressing the initial information and most adequately describes the vector time series of full-scale and model data restricted by a set of statistical characteristics in the invariant form. For an express analysis of correlation of the modeling data and in situ （or satellite derived） data a system of simplified correlation invariant indicators was used. This methodology was applied for validation of vector values fields at the first time. The method gives an opportunity to describe a field of a vector correlation and detect an areas with different levels of correlation between model and in situ （or other reference） vector data. The work was carried out in the frame of the My Ocean Project （FP7）.

An edge-adaptive demosaicking method based on image correlation

To reduce the cost, size and complexity, a consumer digital camera usually uses a single sensor overlaid with a color filter array(CFA) to sample one of the red-green-blue primary color values, and uses demosaicking algorithm to estimate the missing color values at each pixel. A novel image correlation and support vector machine(SVM) based edge-adaptive algorithm was proposed, which can reduce edge artifacts and false color artifacts, effectively. Firstly, image pixels were separated into edge region and smooth region with an edge detection algorithm. Then, a hybrid approach switching between a simple demosaicking algorithm on the smooth region and SVM based demosaicking algorithm on the edge region was performed. Image spatial and spectral correlations were employed to create middle planes for the interpolation. Experimental result shows that the proposed approach produced visually pleasing full-color result images and obtained higher CPSNR and smaller S-CIELAB*ab?E than other conventional demosaicking algorithms.

Isotopic Effects on Stereodynamics for Ca＋HCI, Ca＋DCI, and Ca＋TCl Reactions

The vector correlations in Ca＋HCl, Ca＋DCl, and Ca＋TCl reactions have been investigated by means of the quasi-classical trajectory calculations on PES constructed by means of multireference configuration interaction. The distributions of P（θr）, P（Фr） and the PDDCSs of （2π/σ）（dσ00/dωt）, （2π/σ）（dσ20/dωt）, （2π/σ）（dσ22＋/dωt）, （2π/σ）（dσ21-/dωt） have been calculated based on the surface. The remarkable isotopic effects in the reactions are observed, and the mechanism which may be ascribed to different mass factors is discussed.

Theoretical Study on Stereodynamics of Reactions of N（^2D）＋H2→NH＋H and N（^2D）＋D2→ND＋D

The vector correlations between products and reagents for the title reactions have been calculated by the quasi-classical trajectory method at a collision energy of 21.32 kJ/mol on an accurate potential energy surface of Ho et al. （J. Chem. Phys. 119, 3063 （2003））. The peaks of the product angular distribution are found to be in both backward and forward directions for the two title reactions. The product rotational angular momentum is not only aligned, but also oriented along the negative direction of y-axis. These theoretical results are in good agreement with recent experimental findings for the two title reactions. The isotopic effect is also revealed and primarily attributed to the difference of the mass factor in the two title reactions.

Influence of Vibrational Excitation on Stereodynamics for O（3P）＋D2→OD＋D Reaction

Theoretical investigations on the stereodynamics of the O（3P）＋D2 reaction have been calculated by means of the quasi-classical trajectory to study the product rotational polarization at collision energy of 104.5 k J/tool on the potential energy surface of the ground 3A＂ triplet state. The vector properties including angular momentum alignment distributions and four polarization dependent generalized differential cross-sections of product have been presented. Furthermore, the influence of reagent vibrational excitation on the product vector properties has also been studied. The results indicate that the vector properties are sensitively affected by reagent vibrational excitation.

Influence of rotational excitation and collision energy on the stereo dynamics of the reaction:N(~4S)+H_2 (v=0,j=0,2,5,10)→NH(X^3Σ^-)+H

The N＋H2 reaction has attracted a great deal of attention from both the experimental and the theoretical community, and most of the attention has been paid to the first excited state N （2 D） atoms in collisions with hydrogen molecules and the scalar properties of the reaction. In this paper, we study the stereo dynamical properties and calculate the reaction cross sections of the N（4S） ＋ H2 （v=0, j=0, 2, 5, 10） → NH（X3∑-） ＋ H using the quasi-classical trajectory （QCT） method on an accurate NH2 potential energy surface （PES） reported by Poveda and Varandas [Poveda L A and Varandas A J C 2005 Phys. Chem. Chem. Phys. 7 28671, in a collision energy range of 25 kcal.mol-1 -140 kcal.mol-1. Results indicate that the reactant rotational excitation and initial collision energy both have a considerable influence on the distributions of the k-j＇ correlation, the k-k＇-j＇ correlation and k-k＇ correlation. The differential cross section is found to be sensitive to collision energy.

Stereodynamics study of reactions N（2D）＋HD→NH＋D and ND＋H

The product polarizations of the title reactions are investigated by employing the quasi-classical trajectory （QCT） method. The four generalized polarization-dependent differential cross-sections （PDDCSs） （2π/σ）（dσ00/dωt）, （2π/σ）（dσ20/dωt）, （2π/σ）（dσ22＋/dωt）, and （2π/σ）（dσ21-/dωt） are calculated in the centre-of-mass frame. The distribution of the angle between κ and j＇, P（θr）, the distribution of the dihedral angle denoting κ-κ＇-j＇ correlation, P（Фr）, as well as the angular distribution of product rotational vectors in the form of polar plots P（θr, Фr） are calculated. The isotope effect is also revealed and primarily attributed to the difference in mass factor between the two title reactions.

Effects of the vibrational and rotational excitation of reagent on the stereodynamics of the reaction S (3P) ＋ H2→ SH ＋ H

Quasiclassical trajectory （QCT） calculations are first carried out to study the stereodynamics of the S （3p） ＋ H2 → SH ＋ H reaction based on the ab initio 13Atr potential energy surface （PES） （Lii etal. 2012 J. Chem. Phys. 136 094308）. The QCT-calculated reaction probabilities and cross sections for the S ＋ H2 （v = 0, j = 0） reaction are in good agreement with the previous quantum mechanics （QM） results. The vector properties including the alignment, orientation, and polarization- dependent differential cross sections （PDDCSs） of the product SH are presented at a collision energy of 1.8 eV. The effects of the vibrational and rotational excitations of reagent on the stereodynamics are also investigated and discussed in the present work. The calculated QCT results indicate that the vibrational and rotational excitations of reagent play an important role in determining the stereodynamic properties of the title reaction.

The effect of the rotational excitation of NO on the stereodynamics for the reaction C(~3P)+NO(X^2Π)→CN(X^2Σ^+)+O(~3P)

The stereodynamic properties of the reaction C （^3P） ＋ NO （X2^П） →CN （X^2∑^＋） ＋ O （^3P） in different rotational states of reactant NO are studied theoretically by using the quasiclassical trajectory method on ^2A″ and ^2A′ potential energy surfaces （PESs） at a collision energy of 0.06 eV. The vector properties in different rotational states on the two surfaces are discussed in detail. The results indicate that the rotational excitation of NO has considerable influence on the stereodynamic property of the reaction occurring on the two surfaces. At the same time, the calculated polarization-dependent differential cross sections （PDDCSs） in different initial rotational states manifest that products are strongly polarized at three scattering angles.

Molecular Frame Photoemission： Probe of the Photoionization Dynamics for Molecules in the Gas Phase

Molecular frame photoemission is a very sensitive probe of the photoionization （PI） dynamics of molecules. This paper reports a comparative study of non-resonant and resonant photoionization of D2 induced by VUV circularly polarized synchrotron radiation at SOLEIL at the level of the molecular frame photoelectron angular distributions （MFPADs）. We use the vector correlation method which combines imaging and time-of-flight resolved electron-ion coincidence techniques, and a generalized formalism for the expression of the Ⅰ（χ, θe, Фe） MFPADs, where χ is the orientation of the molecular axis with respect to the light quantization axis and （θe, Фe） the electron emission direction in the molecular frame. Selected MFPADs for a molecule aligned parallel or perpendicular to linearly polarized light, or perpendicular to the propagation axis of circularly polarized light, are presented for dissociative photoionization （DPI） of D2 at two photon excitation energies, hv=19 eV, where direct PI is the only channel opened, and hv=32.5 eV, i.e. in the region involving resonant excitation of Q1 and Q2 doubly excited state series. We discuss in particular the properties of the circular dichroism characterizing photoemission in the molecular frame for direct and resonant PI. In the latter case, a remarkable behavior is observed which may be attributed to the interference occurring between undistinguishable autoionization decay channels.

Effect of the reagent vibration on stereodynamics of the reaction O（^1D）＋HF→F＋OH

This paper studies the influence of the reagent vibration on the reaction O（1D）＋HF→HO＋F by using a quasiclassical trajectory method on the new ab initio 1A＇ ground singlet potential energy surface （Gomez-Carrasco et al 2007 Chem. Phys. Lett. 435 188 193）. The product angular distributions which reflect the vector correlation are calculated. Four polarization-dependent differential cross sections （PDDCSs） which are sensitive to many photoinitiated bimolecular reaction experiments are presented in the center of the mass frame, respectively. The differential cross section indicates that the OH product mainly tends to the forward scattering, and other PDDCSs are also influenced by the vibration levels of HF.

Influence of the reagent vibration on the stereodynamics of the reactions D^-+H_2 and H^-+D_2

Employing the quasi-classical trajectory method and the potential energy surface of Panda and Sathyamurhy [Panda A N and Sathyamurthy N 2004 J. Chem. Phys. 121 9343], the effect of the reagent vibration on vector correlation of the ion-molecule reactions D- ＋ H2 and H- ＋ D2 is studied at a collision energy of 35.7 kcal/mol. Four generalized polarization-dependent differential cross sections （2π/σ） （dσ00/dωt）, （2π/σ） （dσ20/dσ20）, （27π/σ） （dσ22＋/dwt）, and （2π/σ）（dπ/σ） are presented in the centre-of-mass reference frame, separately. At the same time, the effects on the product angular distributions P（θr）, P（~r） and P（Oφ） of the title reactions are also analysed. The calculated results show that the scattering tendencies of the product HD, the alignment and the orientation of j^1 sensitively depend on reagent molecule vibration.

The polarization dependent differential cross sections of the reactions:H+LiH^+(v=0,j=0)→H_2+Li^+ and H^++ LiH(v=0,j=0)→H_2^++Li

Quasi-classical trajectory(QCT) calculations have been carried out to study the generalized polarization dependent differentialcross sections(PDDCSs) for the reactions H + LiH^+(v = 0,j = 0)→H_2 + Li^+ and H^+ + LiH(v = 0,j = 0)→H_2^+ + Li occurring onthe two lowest-lying electronic states of the LiH_2^+ system,using the ab initio potential energy surfaces(PESs) of Martinazzo et al.[3].Four PDDCSs,i.e.,(2π/σ)(dσ_(00)/dω_t),(2π/σ)(dσ_(20)/dω_t),(2π/σ)(dσ_(22+)/dω_t),(2π/σ)(dσ_(21-)/dω_t) have been discussed ...

A theoretical study of the stereodynamics on the abstraction reactions H/D+HS/DS

The quasi-classical trajectory （QCT） method is employed to calculate the stereodynamics of the abstraction reactions H/D ＋ HS/DS based on an accurate potential energy surface [Lti S J, Zhang P Y, Han K L and He G Z 2012 J. Chem. Phys. 136 094308]. The reaction cross sections of the title reaction are computed, and the vector correlations for different collision energies and different initial vibrational states are presented. The influences of the collision energy and reagent vibration on the product polarization are studied, and the product polarizations of the title reactions are found to be distinctly different, which arises from the different mass factors, collision energies, and reagent vibrational states.

The collision energy effect on the stereodynamics of the Ca + HCl→CaCl + H reaction

The stereodynamics of the reaction of Ca ＋ HCl are calculated at three different collision energies based on the potential energy surface [Verbockhaven G et al. 2005 J. Chem. Phys. 122 204307] using quasi-classical trajectory theory. The polarization-dependent differential cross sections （PDDCSs） （2π/σ ）（dσ 00 /dω t ）, （2π/σ ）（dσ 20 /dωt ）, （2π/σ ）（dσ 22＋ /dωt ）, （2π/σ ）（dσ 21 /dω t ） and the distributions of P（θ r ）, P（φr ）, and P（θr ,φr ） are calculated. The results indicate that the rotational polarization of the CaCl product presents different characteristics for the different collision energies, and the effects of the collision energy on the vector potential, including the alignment, orientation, and PDDCSs, are not obvious.

The effect of collision energy on the stereodynamics of the reaction H(~2S)+NH(X^3∑^-,v = 0,j = 0)→ N(~4S)+H_2

The quasi-classical trajectory （QCT） is calculated to study the stereodynamics properties of the title reaction H（^2S） ＋ NH （X^3 ∑^-, v = 0, j = 0）→ N（^4S） ＋ H2 on the ground state ^4A″ potential energy surface （PES） constructed by Zhai and Han [2011 Jr. Chem. Phys. 135 104314]. The calculated QCT reaction probabilities and cross sections are in good agreement with the previous theoretical results. The effects of the collision energy on the k-kt distribution and the product polarization of H2 are studied in detail. It is found that the scattering direction of the product is strongly dependent on the collision energy. With the increase in the collision energy, the scattering directions of the products change from backward scattering to forward scattering. The distribution of P（Or） is strongly dependent on the collision energy below the lower collision energy （about 11.53 kcal/mol）. In addition, the P（（Pr） distribution dramatically changes as the collision energy increases. The calculated QCT results indicate that the collision energy plays an important role in determining the stereodynamics of the title reaction.

Stereodynamics of the reactions Ne+H_2^+/Ne+D_2^+/Ne+T_2

The vector correlations between products and reagents for the reactions Ne＋H2＋, Ne＋D2＋, and Ne＋T2＋ are calculated by means of the quasi-classical trajectory method on a new potential energy surface constructed by Lfi et al, [J. Chem. Phys. 2010 132, 014303]. The polarization-dependent differential cross-sections （27π/σ）（dσ00/dωt）, （2π/σ）（dσ20/dwt）, （27π/σ）（dσ22＋/dwt）, and （2π/σ）（dσ21-/dwt）, and the distributions of P（θr）, P（φ）, and P（θr, Cr） are calculated. The isotopic effect, which is associated with the difference in mass factor among the three reactions, is revealed.