Numerical calculations of the kinetic energy of various extensions of the one-dimensional Hubbard model including dimerization and repulsion between nearest neighbors are reported. Using the sum rule that relates the kinetic energy to the integral of the optical conductivity, one can detemine which parameters are consistent with the reduction of the infrared oscillator strength that has been observed in the Bechgaard salts. This leads to improved estimates of the correlation parameters for both the tetramethyltetraselenafulvalene and tetramethyltetrathiafulvalene series.

• Received 24 February 1995

DOI:https://doi.org/10.1103/PhysRevB.52.4788