Mechanism for large thermoelectric power in negative-U molecular quantum   dots
  We investigate with the aid of numerical renormalization group techniques the thermoelectric properties of a molecular quantum dot described by the negative-U Anderson model. We show that the charge Kondo effect provides a mechanism for enhanced thermoelectric power via a correlation induced asymmetry in the spectral function close to the Fermi level. We show that this effect results in a dramatic enhancement of the Kondo induced peak in the thermopower of negative-U systems with Seebeck coefficients exceeding 50$\mu V/K$ over a wide range of gate voltages. 
S. Andergassen, T. A. Costi, V. Zlatic
cond-mat.mes-hall cond-mat.str-el