Dipole Polarizability of the Neutral Carbon Atom and the Dipole-Dipole Interaction between Carbon Atoms

Many-body perturbation theory is used to calculate the dipole polarizability αd of the neutral carbon atom in its ³P ground state. The result is 2.38 ³ in lowest order. When correlations are included by calculating higher-order terms in the perturbation expansion, we obtain the value 1.54 ³ for αd averaged over ML values. A calculation of the coefficient of the R^-6 term in the van der Waals interaction between two carbon atoms each in the ³P ground state is also reported.