Reduced dimension discrete variable representation study of cis–trans isomerization in the S1 state of C2H2
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
- Univ. of California, Berkeley, CA (United States)
- Univ. of California at San Francisco, San Francisco, CA (United States)
- The Univ. of Texas at Austin, Austin, TX (United States)
Isomerization between the cis and trans conformers of the S1 state of acetylene is studied using a reduced dimension discrete variable representation (DVR) calculation. Existing DVR techniques are combined with a high accuracy potential energy surface and a kinetic energy operator derived from FG theory to yield an effective but simple Hamiltonian for treating large amplitude motions. The spectroscopic signatures of the S1 isomerization are discussed, with emphasis on the vibrational aspects. The presence of a low barrier to isomerization causes distortion of the trans vibrational level structure and the appearance of nominally electronically forbidden $$\tilde{A}$$1A2 ← $$\tilde{X}$$1Σ$$^+_g$$ transitions to vibrational levels of the cis conformer. Both of these effects are modeled in agreement with experimental results, and the underlying mechanisms of tunneling and state mixing are elucidated by use of the calculated vibrational wavefunctions.
- Research Organization:
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- FG02-87ER13671
- OSTI ID:
- 1557690
- Journal Information:
- Journal of Chemical Physics, Vol. 134, Issue 24; ISSN 0021-9606
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Full-dimensional quantum mechanics calculations for the spectroscopic characterization of the isomerization transition states of HOCO/DOCO systems
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journal | January 2018 |
One-colour (∼220 nm) resonance-enhanced (S 1 − S 0 ) multi-photon dissociation of acetylene: probe of the C 2 A 1 Π u − X 1 Σ + g band by frequency-modulation spectroscopy
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journal | February 2020 |
Phase-Space Approach to Solving the Time-Independent Schrödinger Equation
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journal | August 2012 |
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