%0 Journal Article %1 hlwoodcock:L.1998-a %A Kaledin, A. L. %A Heaven, M. C. %A Lawrence, W. G. %A Cui, Q. %A Stevens, J. E. %A Morokuma, K. %D 1998 %J J. Chem. Phys. %K atoms temperature-dependence states perturbation- theory electronic-structure 2nd spin energy 2nd-order bibtex-import system derivatives configuration-interaction calculations %N 7 %P 2771--2783 %T Ab initio molecular-orbital study of the trichlorine radical, cl-3 %V 108 %X We report a rigorous ab initio study of the ground and low- lying excited-state potential-energy surfaces (PESs) of the Cl- 2 radical at CASSCF, CASPT2, and MRSDCI levels of theory. The ground state has two Cl ... Cl-2 van der Waals complexes, (X) over tilde L and (X) over tilde'B. The linear asymmetric minimum ((X) over tilde L) is (II)-I-2, with a Cl-Cl distance r = 3.90 bohr, and a Cl-M (M: the Cl-2 center-of-mass) distance R = 8.70 bohr. The bent asymmetric minimum ((X) over tilde'B) is of (2)A' symmetry, with r = 3.90 bohr, R = 6.85 bohr, and the angle between (r) over cap and (R) over cap, gamma = 68.4 degrees. Spin-orbit CI (configuration interaction) predicts that the global minimum is linear (X) over tilde L ((II3/2)-I- 2) with a bond dissociation energy of D-e(Cl-2((X) over tilde)- Cl) of 280 cm(-1). Low-lying doublet excited states have only one strongly bound structure, a linear symmetric (A) over tilde L (1 (IIg)-I-2) state with a bond distance of 4.67 bohr. This state is bound by similar to 4300cm(-1) with respect to the Cl- 2((II3/2)-I-3)+Cl asymptote, and its minimum lies about 8700 cm(-1) above the (X) over tilde L van der Waals minimum. Transition dipole moment calculations show that the (A) over tilde-(X) over tilde transition is fully allowed. Two bound quartet minima were located. The most deeply bound was QD3h (1 (4)A(1)') With a D-3h equilibrium geometry (r = 5.00 bohr) about 11 300 cm(-1) above (X) over tilde L. The other state, QC2v (1 (4)A(2)) had a C-2v equilibrium geometry (r(1) = 4.83 bohr and theta = 101.7 degrees) and an energy of about 13 500 cm(-1) relative to (X) over tilde L. Although Cl-3((X) over tilde) is shown to be unstable, the present results support the notion that Cl-3 participates in Cl atom recombination processes. However, the energies and transition moments of the low-lying excited states are not consistent with electronic spectra that have been tentatively assigned to Cl-3. (C) 1998 American Institute of Physics.

@article{hlwoodcock:L.1998-a, abstract = {We report a rigorous ab initio study of the ground and low- lying excited-state potential-energy surfaces (PESs) of the Cl- 2 radical at CASSCF, CASPT2, and MRSDCI levels of theory. The ground state has two Cl ... Cl-2 van der Waals complexes, (X) over tilde L and (X) over tilde'B. The linear asymmetric minimum ((X) over tilde L) is (II)-I-2, with a Cl-Cl distance r = 3.90 bohr, and a Cl-M (M: the Cl-2 center-of-mass) distance R = 8.70 bohr. The bent asymmetric minimum ((X) over tilde'B) is of (2)A' symmetry, with r = 3.90 bohr, R = 6.85 bohr, and the angle between (r) over cap and (R) over cap, gamma = 68.4 degrees. Spin-orbit CI (configuration interaction) predicts that the global minimum is linear (X) over tilde L ((II3/2)-I- 2) with a bond dissociation energy of D-e(Cl-2((X) over tilde)- Cl) of 280 cm(-1). Low-lying doublet excited states have only one strongly bound structure, a linear symmetric (A) over tilde L (1 (IIg)-I-2) state with a bond distance of 4.67 bohr. This state is bound by similar to 4300cm(-1) with respect to the Cl- 2((II3/2)-I-3)+Cl asymptote, and its minimum lies about 8700 cm(-1) above the (X) over tilde L van der Waals minimum. Transition dipole moment calculations show that the (A) over tilde-(X) over tilde transition is fully allowed. Two bound quartet minima were located. The most deeply bound was QD3h (1 (4)A(1)') With a D-3h equilibrium geometry (r = 5.00 bohr) about 11 300 cm(-1) above (X) over tilde L. The other state, QC2v (1 (4)A(2)) had a C-2v equilibrium geometry (r(1) = 4.83 bohr and theta = 101.7 degrees) and an energy of about 13 500 cm(-1) relative to (X) over tilde L. Although Cl-3((X) over tilde) is shown to be unstable, the present results support the notion that Cl-3 participates in Cl atom recombination processes. However, the energies and transition moments of the low-lying excited states are not consistent with electronic spectra that have been tentatively assigned to Cl-3. (C) 1998 American Institute of Physics.}, added-at = {2006-06-16T05:03:46.000+0200}, author = {Kaledin, A. L. and Heaven, M. C. and Lawrence, W. G. and Cui, Q. and Stevens, J. E. and Morokuma, K.}, biburl = {https://www.bibsonomy.org/bibtex/2488ca821c5036be5665d9eb76ef51d65/hlwoodcock}, citeulike-article-id = {569413}, comment = {ZW144 J CHEM PHYS}, interhash = {a94cea02aba2dfa9f2e65cf3cf6b3b83}, intrahash = {488ca821c5036be5665d9eb76ef51d65}, journal = {J. Chem. Phys.}, keywords = {atoms temperature-dependence states perturbation- theory electronic-structure 2nd spin energy 2nd-order bibtex-import system derivatives configuration-interaction calculations}, number = 7, pages = {2771--2783}, priority = {2}, timestamp = {2006-06-16T05:03:46.000+0200}, title = {Ab initio molecular-orbital study of the trichlorine radical, cl-3}, volume = 108, year = 1998 }