Theoretical Study of the vdW Complex Cd···N2

2008 ◽  
Vol 73 (10) ◽  
pp. 1357-1371 ◽  
Author(s):  
Michal Ilčin ◽  
Vladimír Lukeš ◽  
Viliam Laurinc ◽  
Stanislav Biskupič
Keyword(s):  
Ground State ◽  
Energy Surface ◽  
Theoretical Study ◽  
Van Der Waals ◽  
Nitrogen Molecule ◽  
Temperature Dependences ◽  
Bond Functions ◽  
Well Depth ◽  
Coefficient Of Diffusion ◽  
Electronic Ground

The supermolecular CCSD(T) ab initio calculations of potential energy surface for the electronic ground state of van der Waals complex formed from a cadmium atom and a nitrogen molecule are presented. Our calculations indicate the bent orientation (Jacobi coordinates are rN-N = 1.10 Å, R = 4.53 Å, angle θ = 62°) of the van der Waals (vdW) system with a well depth of De = 73.3 cm-1. This well depth was shifted to the value of 76.7 cm-1 by systematical extension of mid-bond functions. The temperature dependences of the theoretical coefficient of diffusion were evaluated from the molecular dynamics and the Enskog-Chapman theory. The theoretical values at 273 K are compared with the available experimental data.

Theoretical Study of H2...I- van der Waals Anion Complex

2005 ◽  
Vol 70 (6) ◽  
pp. 797-810 ◽  
Author(s):  
Michal Ilčin ◽  
Vladimír Lukeš ◽  
Viliam Laurinc ◽  
Stanislav Biskupič
Keyword(s):  
Interaction Energy ◽  
Energy Surface ◽  
Theoretical Study ◽  
Van Der Waals ◽  
Dispersion Forces ◽  
Physical Origin ◽  
Anion Complex ◽  
Linear Configuration ◽  
Well Depth ◽  
Hf Wave

The ab initio potential energy surface (PES) for the weak interaction of hydrogen molecule with iodine anion is presented. The surface was obtained by the supermolecular method at the MP4(SDTQ) level of theory. Our calculations indicate the van der Waals (vdW) system for the linear configuration at rH-H = 0.752 Å and R = 3.76 Å with a well depth of De = 2096 μEh. The presented PES reveals also a transition state for the perpendicular arrangement at rH-H = 0.7416 Å and R = 4.63 Å with an interaction energy of -113 μEh. The physical origin of stability of the vdW H2...I- structure with respect to the H2...X- (X = F, Cl, Br) one was analysed by the symmetry adapted perturbation theory (SAPT) based on the single determinant HF wave function. The separation of the interaction energy shows that the dispersion forces play a much more important role for the systems with Cl, Br and I than for H2...F- and their importance slightly increases in the order Cl < Br < I. The global importance of the electrostatic and the induction energies decreases in the order F > Cl > Br > I.

Theoretical Study of the Dissociation and Isomerization of NCS

2003 ◽  
Vol 217 (3) ◽  
pp. 255-264 ◽  
Author(s):  
M. Diehr ◽  
G. Chambaud ◽  
H.-J. Werner
Keyword(s):  
Excited States ◽  
Dissociation Energy ◽  
Ground State ◽  
Spectroscopic Data ◽  
Large Scale ◽  
Theoretical Study ◽  
Ground States ◽  
Electronic Ground State ◽  
Barrier Heights ◽  
Electronic Ground

AbstractLarge scale MRCI calculations have been performed to study the electronic ground state and low-lying excited states of the NCS molecule and its isomers. The isomer CNS is found to be stable and linear. It lies 1.29 eV higher in energy than NCS, while CSN has a much higher energy and is unstable. The dissociation energy of the NCS isomer has been calculated to be 4.25 eV. The isomerization paths between the 2Π ground states of both isomers have been mapped by CASSCF and MRCI calculations. The barriers for the NCS → CNS isomerization in 2A′ and 2A″ symmetry have cyclic forms and the barrier heights have been calculated to be 2.71 eV and 2.44 eV, respectively (MRCI). For both isomers, the collinear dissociation paths to the (diatomic + atom) fragments have been investigated by CASSCF calculations. Spectroscopic data are given for the X2Π ground state and for the A2Σ+ state of CNS. The results are compared with the valence isoelectronic system NCO.

scholarly journals Radiative cooling of H3O+ and its deuterated isotopologues

2016 ◽  
Vol 18 (37) ◽  
pp. 26268-26274 ◽  
Author(s):  
Vladlen V. Melnikov ◽  
Sergei N. Yurchenko ◽  
Jonathan Tennyson ◽  
Per Jensen
Keyword(s):  
Dipole Moment ◽  
Potential Energy ◽  
Ab Initio ◽  
Ground State ◽  
Theoretical Study ◽  
Electronic Ground State ◽  
Radiative Cooling ◽  
Radiative Lifetimes ◽  
Hydronium Ion ◽  
Electronic Ground

In conjunction with ab initio potential energy and dipole moment surfaces for the electronic ground state, we have made a theoretical study of the radiative lifetimes for the hydronium ion H3O+ and its deuterated isotopologues.

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