Symmetry breaking in linear : A theoretical study

✍ Scribed by Wenli Zou; Dong Xu; Peter Zajac; Andrew L. Cooksy; Isaac B. Bersuker; Yang Liu; James E. Boggs

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 613 KB
• Volume: 978
• Category: Article
• ISSN: 0022-2860
• DOI: 10.1016/j.molstruc.2010.03.082

✦ Synopsis

The four lowest excited states ( 2 P g , 2 P u , 2 R þ u , and 2 R þ g ) of ZnCl þ 2 are calculated using the EOMIP-CCSD method and the spectroscopic constants are reported. It is found that all the states have linear structures, while the 2 P g and 2 R þ u states are noncentrosymmetric with two equivalent global minima due to the pseudo Jahn-Teller effect. The computed barriers between the two minima are 88 and 169 cm À1 , respectively, being much smaller and more reliable than the previous published multi-configurational results because of inaccurate treatment of the static correlation in the latter. For the ground 2 P g state, anharmonic vibrational levels are also simulated using the finite element method. It shows that the configuration of the vibronic ground state is also noncentrosymmetric.