(PEDT-TSF)(2)FeCl4 is the first kappa-type organic metal based on an asymmetric pi donor with a pyrazine ring, PEDT-TSF. (PEDT-TSF)(2)FeBr4 has another type of metallic layers composed of unique tetradic PEDT-TSF columns, suggesting that PEDT-TSF is a suitable donor to afford metallic conductors. The extended Huckel tight-binding band examination showed a suitable choice of the atomic orbital parameters to be essential to obtain reasonable results.