Anchoring the Potential Energy Surface of the Diacetylene Dimer

Abstract

The diacetylene dimer, (H-CC-CC-H)2, serves as a useful prototype for delocalised -type interactions. It mimics many of the important characteristics of aromatic -stacking prototypes such as (C6H6)2 but is small enough that full geometry optimisations and vibrational frequency computations with analytic derivatives are feasible with sophisticated electronic structure techniques. Six stationary points on the potential energy surface (PES) of (H-CC-CC-H)2 have been identified and characterised with CCSD(T) computations. The relative energies of the stationary points on each PES have been anchored by combining explicitly correlated MP2-R12 computations with corrections for higher-order correlation effects as well as core correlation effects. These computations identify a Y-shaped global minimum with an electronic dissociation energy (De) of 1.84 kcal mol-1 at the all-electron CCSD(T) complete basis set limit. Higher-order correlation corrections are necessary to correctly identify the global minimum while core correlation effects have almost no influence on the relative energies of the stationary points.

Department(s)

Chemistry

Comments

National Science Foundation, Grant CHE-0517067

Keywords and Phrases

-type interactions; Diacetylene dimer; Potential energy surface

International Standard Serial Number (ISSN)

1362-3028; 0026-8976

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 Taylor and Francis Group; Taylor and Francis, All rights reserved.

Publication Date

01 Jan 2009

Link to Full Text

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