Two-band system: A candidate for new molecular materials

We describe the two-band system, where two bands with different characters coexist near the Fermi level, as a candidate for new molecular conductors. An interplay of these two bands would provide unique physical properties. (DCNQI)2Cu (one-dimensional (1D)LUMO and 3D dxy bands), Pd(dmit)2 salts (1DLUMO and 2D HOMO bands), and (TMET-STF)2BF4 (1D HOMO and 2D HOMO bands) would be classified into this two-band system. In the two-band molecular system, new degrees of freedom would be introduced and the tuning of the band-filling would be possible.