scholarly journals Three-dimensional potential energy surfaces of ArNO (X̃ 2Π)

2020 ◽  
Vol 152 (11) ◽  
pp. 114302
Author(s):  
Alexander Teplukhin ◽  
Brian K. Kendrick
Keyword(s):  
Potential Energy ◽  
Potential Energy Surfaces ◽  
Three Dimensional ◽  
Energy Surfaces

THEORETICAL TRANSITION PROBABILITIES FOR THE $\tilde{A}^{2}A_{1} -\tilde{X}^{2}B_{1}$ SYSTEM OF H2O+ AND D2O+ AND RELATED FRANCK–CONDON FACTORS BASED ON GLOBAL POTENTIAL ENERGY SURFACES

2005 ◽  
Vol 04 (01) ◽  
pp. 225-245 ◽  
Author(s):  
IKUO TOKUE ◽  
KATSUYOSHI YAMASAKI ◽  
SATOSHI MINAMINO ◽  
SHINKOH NANBU
Keyword(s):  
Potential Energy ◽  
Photoelectron Spectroscopy ◽  
Potential Energy Surfaces ◽  
Least Squares Method ◽  
Transition Probabilities ◽  
Three Dimensional ◽  
Equilibrium Geometry ◽  
Condon Factors ◽  
Energy Surfaces ◽  
Franck Condon

To elucidate the ionization dynamics, in particular the vibrational distribution, of H 2 O +(Ã) produced by photoionization and the Penning ionization of H 2 O and D 2 O with He *(2 3S) atoms, Franck–Condon factors (FCFs) were given for the [Formula: see text] ionization, and the transition probabilities were presented for the [Formula: see text] emission. The FCFs were obtained by quantum vibrational calculations using the three-dimensional potential energy surfaces (PESs) of [Formula: see text] and [Formula: see text] electronic states. The global PESs were determined by the multi-reference configuration interaction calculations with the Davidson correction and the interpolant moving least squares method combined with the Shepard interpolation. The obtained FCFs exhibit that the [Formula: see text] state primarily populates the vibrational ground state, as its equilibrium geometry is almost equal to that of [Formula: see text], while the bending mode (ν2) is strongly enhanced for the H 2 O +(Ã) state; the maximums in the population of H 2 O + and D 2 O + are approximately v2 = 11–12 and 15–17, respectively. These results are consistent with the distributions observed by photoelectron spectroscopy. Transition probabilities for the [Formula: see text] system of H 2 O + and D 2 O + show that the bending progressions consist primarily of the [Formula: see text] emission, with combination bands from the (1, v′2 = 4–8, 0) level being next most important.

POTENTIAL ENERGY SURFACES AND MICROWAVE SPECTRA FOR 20Ne–13C16O2, 22Ne–12C16O2 and 22Ne–13C16O2 COMPLEXES

2012 ◽  
Vol 11 (06) ◽  
pp. 1175-1182 ◽  
Author(s):  
RONG CHEN ◽  
HUA ZHU
Keyword(s):  
Potential Energy ◽  
Potential Energy Surfaces ◽  
Global Minimum ◽  
Energy Levels ◽  
Three Dimensional ◽  
Lanczos Algorithm ◽  
Potential Surfaces ◽  
Microwave Spectra ◽  
Stretching Vibration ◽  
Energy Surfaces

We report averaged potential energy surfaces for isotopic Ne–CO2 complexes (20 Ne –13 C 16 O 2, 22 Ne –12 C 16 O 2 and 22 Ne –13 C 16 O 2). According to the latest ab initio potential of 20 Ne –12 C 16 O 2 (Chen R, Jiao EQ, Zhu H, Xie DQ, J Chem Phys133:104302, 2010) including the Q3 normal mode for the υ3 antisymmetric stretching vibration of the CO2 molecule. We obtain the averaged potentials for 20 Ne –13 C 16 O 2, 22 Ne –12 C 16 O 2 and 22 Ne –13 C 16 O 2 by the integration of the three-dimensional potential over the Q3 coordinate. The averaged potential surfaces are found to have a T-shaped global minimum and two equivalent linear local minima. The radial DVR/angular FBR method and the Lanczos algorithm are applied to calculate the rovibrational energy levels. Comparison with the available observed values showed an overall excellent agreement for all spectroscopic parameters and the microwave spectra.

scholarly journals Computational Study of Inversion-topomerization Pathways in 1,3-Dimethylcyclohexane and 1,4-Dimethylcyclohexane: Ab Initio Conformational Analysis

2020 ◽  
Author(s):  
Huiting Bian ◽  
Yifan Zhang ◽  
Yongjin Wang ◽  
Jun Zhao ◽  
Xiaohui Ruan ◽  
...  
Keyword(s):  
Potential Energy ◽  
Conformational Analysis ◽  
Potential Energy Surfaces ◽  
Computational Study ◽  
Three Dimensional ◽  
Boltzmann Distribution ◽  
Molecular Structures ◽  
Stationary Points ◽  
Energy Surfaces ◽  
Cis And Trans

This work concerns the typical conformational behaviors for di-substituted cyclohexanes that inherently depend on spatial orientations of side chains in flexible cyclic ring. The 1,3-dimethylcyclohexane and 1,4-dimethylcyclohexane in both cis- and trans-configurations were focused here to unravel their conformational inversion-topomerization mechanisms. Full geometry optimizations were performed at B3LYP/6-311++G(d,p) level of theory to explicitly identify all distinguishable molecular structures, and thus explore potential energy surfaces (PES) of the complete interconversion routes for two stereoisomers of 1,3-dimethylcyclohexane and 1,4-dimethylcyclohexane. Additional quantum calculations were carried out by separately applying MP2/6-311++G(d,p), G4, and CCSD(T)/6-311++G(d,p) methods to further refine all PES’ stationary points. With respect to quantum results, the conformational analysis was conducted to gain insight into the determination, thermodynamic stabilities, and relative energies of distinct molecular geometric structures. On base of highly biased conformational equilibria, the temperature-dependent populations of stable local minima for four studied dimethylcyclohexanes were obtained by utilizing Boltzmann distribution within 300-2500 K. Moreover, two unique interconversion processes for them, including inversion and topomerization, were fully investigated, and their potential energy surfaces were illustrated with the rigorous descriptions in two or three-dimensional schemes for clarify.

New ab initio potential energy surfaces for the ro-vibrational excitation of OH(X2Π) by He

2014 ◽  
Vol 16 (26) ◽  
pp. 13500-13507 ◽  
Author(s):  
Yulia Kalugina ◽  
François Lique ◽  
Sarantos Marinakis
Keyword(s):  
Potential Energy ◽  
Ab Initio ◽  
Cross Sections ◽  
Differential Cross ◽  
Potential Energy Surfaces ◽  
Vibrational Excitation ◽  
Three Dimensional ◽  
Rate Coefficients ◽  
Differential Cross Sections ◽  
Energy Surfaces

A new, three-dimensional potential energy is presented. Values for integral and differential cross sections, and for inelastic rate coefficients were obtained. The results agree and significantly extend previous studies on OH(X) + He collisions.

scholarly journals Identification of stable adsorption sites and diffusion paths on nanocluster surfaces: an automated scanning algorithm

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Tibor Szilvási ◽  
Benjamin W. J. Chen ◽  
Manos Mavrikakis
Keyword(s):  
Potential Energy ◽  
Potential Energy Surfaces ◽  
Rational Design ◽  
Computational Cost ◽  
Three Dimensional ◽  
Adsorption Sites ◽  
Automated Method ◽  
Diffusion Paths ◽  
Energy Surfaces ◽  
And Diffusion

Abstract The diverse coordination environments on the surfaces of discrete, three-dimensional (3D) nanoclusters contribute significantly to their unique catalytic properties. Identifying the numerous adsorption sites and diffusion paths on these clusters is however tedious and time-consuming, especially for large, asymmetric nanoclusters. Here, we present a simple, automated method for constructing approximate 2D potential energy surfaces for the adsorption of atomic species on the surfaces of 3D nanoclusters with minimal human intervention. These potential energy surfaces fully characterize the important adsorption sites and diffusion paths on the nanocluster surfaces with accuracies similar to current approaches and at comparable computational cost. Our method can treat complex nanoclusters, such as alloy nanoclusters, and accounts for cluster relaxation and adsorbate-induced reconstruction, important for obtaining accurate energetics. Moreover, its highly parallelizable nature is ideal for modern supercomputer architectures. We showcase our method using two clusters: Au18 and Pt55. For Au18, diffusion of atomic hydrogen between the most stable sites occurs via non-intuitive paths, underlining the necessity of exploring the complete potential energy surface. By enabling the rapid and unbiased assessment of adsorption and diffusion on large, complex nanoclusters, which are particularly difficult to handle manually, our method will help advance materials discovery and the rational design of catalysts.

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