skip to main content

SciTech ConnectSciTech Connect

Title: Anharmonic rovibrational calculations of singlet cyclic C{sub 4} using a new ab initio potential and a quartic force field

We report a CCSD(T)/cc-pCV5Z quartic force field (QFF) and a semi-global CCSD(T)-F12b/aug-cc-pVTZ potential energy surface (PES) for singlet, cyclic C{sub 4}. Vibrational fundamentals, combinations, and overtones are obtained using vibrational second-order perturbation theory (VPT2) and the vibrational configuration-interaction (VCI) approach. Agreement is within 10 cm{sup −1} between the VCI calculated fundamentals on the QFF and PES using the MULTIMODE (MM) program, and VPT2 and VCI results agree for the fundamentals. The agreement between VPT2-QFF and MM-QFF results is also good for the C{sub 4} combinations and overtones. The J = 1 and J = 2 rovibrational energies are reported from both VCI (MM) on the PES and VPT2 on the QFF calculations. The spectroscopic constants of {sup 12}C{sub 4} and two C{sub 2v}-symmetry, single {sup 13}C-substituted isotopologues are presented, which may help identification of cyclic C{sub 4} in future experimental analyses or astronomical observations.
Authors:
;  [1] ;  [2] ;  [3]
  1. Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322 (United States)
  2. SETI Institute, 189 Bernardo Ave, Suite 100, Mountain View, California 94043 (United States)
  3. MS 245-1, NASA Ames Research Center, Mofffett Field, California 94035 (United States)
Publication Date:
OSTI Identifier:
22253866
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 139; Journal Issue: 22; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; COMPUTER CALCULATIONS; PERTURBATION THEORY; POTENTIAL ENERGY; SURFACES