dc.contributor.author |
Chaudhuri, R. K |
|
dc.contributor.author |
Feed, K. F |
|
dc.date.accessioned |
2008-09-20T11:39:33Z |
|
dc.date.available |
2008-09-20T11:39:33Z |
|
dc.date.issued |
2008-08-07 |
|
dc.identifier.citation |
Journal of Chemical Physics, Vol. 129, No. 5, pp. 054308 |
en |
dc.identifier.issn |
0021-9606 |
|
dc.identifier.uri |
http://hdl.handle.net/2248/3744 |
|
dc.description.abstract |
The ground state geometries and associated normal mode frequencies of the classical and nonclassical protonated acetylene ion, i.e., the vinyl cation C2H, are computed using the complete active space self-consistent field and improved virtual orbital (IVO) complete active space configuration interaction methods. In addition, the minimum-energy reaction path for the classical to nonclassical interconversion is determined (as are excitation energies) using the IVO modification of multireference Møller–Plesset (MRMP) perturbation theory. The IVO-MRMP treatment predicts the nonclassical structure to be 4.8 kcal/mol more stable than the classical one, which is consistent with other high level theoretical estimates. The proton affinity of acetylene from the IVO-MRMP treatment (154.8 kcal/mol) also agrees well with experiment (153.3 kcal/mol) and with earlier CASPT2 calculations (154.8 kcal/mol). We further report geometries and vibrational frequencies of low lying excited states of C2H, which have not been observed and/or studied before. Comparisons with previous highly correlated calculations further demonstrate the computational efficiency of the IVO-MRPT methods |
en |
dc.language.iso |
en |
en |
dc.publisher |
American Institute of Physics |
en |
dc.relation.uri |
http://link.aip.org/link/?JCPSA6/129/054308/1 |
en |
dc.rights |
© American Institute of Physics |
|
dc.subject |
Moller- Plesset |
en |
dc.subject |
Virtual orbit |
en |
dc.subject |
Acetylene |
en |
dc.title |
Improved virtual orbital multireference Møller–Plesset study of the ground and excited electronic states of protonated acetylene, C2H |
en |
dc.type |
Article |
en |