  Variational, nonrelativisitic energies have been calculated for the ground
state ($^3P_g$) and the lowest quintuplet state ($^5S_u$) of the carbon atom,
with wavefunctions expressed in the basis of symmetry-projected, explicitly
correlated Gaussian (ECG) lobe functions. New exact limits of these energies
have been estimated, amounting to $-37.844906(4)$ and $-37.691751(2)$ hartree.
With finite nuclear masses and leading, scalar relativistic corrections
included, respective experimental excitation energy of $^{12}C$ has been
reproduced with accuracy of about 7 cm$^{-1}$.
