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arXiv · 0803.0946

Fixed-node diffusion Monte Carlo study of the structures of m-benzyne

W. A. Al-Saidi·C. J. Umrigar
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Abstract

Diffusion Monte Carlo (DMC) calculations are performed on the monocyclic and bicyclic forms of m-benzyne, which are the equilibrium structures at the CCSD(T) and CCSD levels of coupled cluster theory. We employed multi-configuration self-consistent field trial wave functions which are constructed from a carefully selected 8-electrons-in-8-orbitals complete active space [CAS(8,8)], with CSF coefficients that are reoptimized in the presence of a Jastrow factor. The DMC calculations show that the monocyclic structure is lower in energy than the bicyclic structure by 1.9(2) kcal/mole, in excellent agreement with the best coupled cluster results.

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W. A. Al-Saidi, C. J. Umrigar. 2008-03-06. Fixed-node diffusion Monte Carlo study of the structures of m-benzyne. https://doi.org/10.1063/1.2902979

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