English

The empirical equilibrium structure of diacetylene

Chemical Physics 2009-11-13 v1

Abstract

High-level quantum-chemical calculations are reported at the MP2 and CCSD(T) levels of theory for the equilibrium structure and the harmonic and anharmonic force fields of diacetylene, HCCCCH. The calculations were performed employing Dunning's hierarchy of correlation-consistent basis sets cc-pVXZ, cc-pCVXZ, and cc-pwCVXZ, as well as the ANO2 basis set of Almloef and Taylor. An empirical equilibrium structure based on experimental rotational constants for thirteen isotopic species of diacetylene and computed zero-point vibrational corrections is determined (r_e^emp: rC-H=1.0615 A, rCtripleC=1.2085 A, rC-C = 1.3727 A) and in good agreement with the best theoretical structure (CCSD(T)/cc-pCV5Z: rC-H=1.0617 Angstrom, rCtripleC=1.2083 A, rC-C=1.3737 A). In addition, the computed fundamental vibrational frequencies are compared with the available experimental data and found in satisfactory agreement.

Keywords

Cite

@article{arxiv.0802.4200,
  title  = {The empirical equilibrium structure of diacetylene},
  author = {S. Thorwirth and M. E. Harding and D. Muders and J. Gauss},
  journal= {arXiv preprint arXiv:0802.4200},
  year   = {2009}
}

Comments

12 pages, accepted for publication in J. Mol. Spectrosc

R2 v1 2026-06-21T10:16:47.583Z