The relative energies of the (X) over tilde, (a) over tilde and (A) over tilde states of CBrCl and its atomization energy in the complete basis limit were determined by extrapolating (spin restricted) CCSD(T), MRCI and EOM-CCSD energies calculated with the aug-cc-pVxZ (x = T, Q, 5) basis sets which were corrected for core-valence correlation, scalar relativistic and spin-orbit coupling effects. The geometries and vibrational frequencies were calculated at the B3LYP/cc-pVTZ density functional and CASPT2/cc-pVTZ levels of theory. The predicted heat of formation at 298 K is 68.0 +/- 1.0 kcal mol(-1). The calculated singlet excited state vibrational frequencies and (A) over tilde <- (X) over tilde excitation energy are in close agreement with experiment. (c) 2005 Elsevier B.V. All rights reserved.