The singlet 3A(g)(-) state that had been theoretically predicted in shorter polyenes [P. Tavan and K. Schulten J. Chem. Phys. 85 (1986) 6602; Phys. Rev. B 36 (1987) 4337] was first identified in bacterial carotenoids by measurements of resonance-Raman excitation profiles. It is almost overlapped with the 1B(u)(+) state in spheroidene (the number of conjugated double bonds, n = 10), and located in-between the 1B(u)(+) and 1B(u)(-) states in lycopene, anhydrorhodovibrin and spirilloxanthin (n = 11-13), The slopes when the 2A(g)(-)- 1B(u)(-)-and 3A(g)(-)-state energies were expressed as linear functions of 1/(2n + 1) exhibited the ratio of 2:3.1:3.8 in excellent agreement with that theoretically predicted, 2:3.1:3.7. (C) 2002 Published by Elsevier Science B.V.