The correlation energy of atomic fluorine

The linked-cluster many-body perturbation theory of Brueckner and Goldstone has been pplied to calculate the correlation energy of atomic fluorine in its ²P ground state. Approximate results using complete orthonormal HFV^n-1HFVⁿOAO and HFSV^n-1 basis sets are reported. A discussion of various basis sets and a comparison between these three is given. The correlation energies computed including only the second-order pair-correlation, hole-hole corrections and the third-order ring diagrams plus three of its exchange counterparts give for these three basis sets — .3039 a.u. — .3230 a.u., and — .3370 a.u., respectively. A discussion of the pair-correlation energies of oxygen, fluorine, and neon is also given.