used for a variety of real systems with good quantita- tive success [11], we do not present it here, but directly describe the electronic transport within LDA+DMFT scheme. The Seebeck coefficient, like the conductivity, is exactly computable within DMFT using the fully renor- malized LDA+DMFT propagators. We generalized the DMFT result [14, 15] to the five-band case relevant for FeSe$_{1}$ − $_{x}$Te$_{x}$ . This involves the following steps: We begin with the general expressions for Seebeck and thermal conductivity, which, respectively, measures the mixed electrical-thermal correlations [ S ( T )] and the heat-current correlations [ k ( T )] at finite T : we show ( dρ$_{dc}$/dT ) and ( d $^{2}$ρ$_{dc}$ /dT $^{2}$) in the top pan- els of Fig. 1. The PG scale, T ∗ is the temperature at which ( dρ$_{dc}$/dT ) shows a maximum, while ( d $^{2}$ρ$_{dc}$ /dT $^{2}$) crosses zero [10]. The Seebeck co-efficient, S ( T ), should also show an anomalous feature, i.e, a minimum, around T ∗ [9, 10]. Very good quantitative agreement with extant data [9, 10] is also clearly visible in S ( T, x ), Fig. 2. Our results are obviously valid only for T > T$_{c}$ , and, at very low T , cor- respond to what would be observed in a non-SC system in absence of disorder. A number of characteristic fea- tures, intimately correlated with those in the resistivity derivatives, are noteworthy: ( i ) S ( T ) is approximately T - independent at T > T$_{min}$ ( x ), in nice accord with Heikes law. Here, it arises due to thermal transport involving Mott localized carriers in our five-orbital Hubbard model. ( ii ) In the relevant range of 0 ≤ x ≤ 0 . 6, we find that S ( T ) smoothly decreases, going through a minimum at another scale T $^{∗}$( x ). Interestingly, the deviation from Heikes law sets in around T$_{PG}$ = 150 K. Further, this scale coincides with the PG scale extracted from resis- tivity derivatives (see Fig. 1), pinning down the temper- ature below which a low energy PG opens up in trans- port. ( iii ) S ( T, x ) crosses zero twice at T$_{low}$ ( x ) , T$_{high}$ ( x ) (labelled T$_{an}$ , T ∗ in Ref. [10]), again in precise accord with data. ( iv ) Even at low T ≃ 10 K, S ( T ) does not recover the linear-in- T form: an examination shows a T η law with η ≤ 1, suggesting that collective bosonic fluctuations dominate the low- T thermopower. ( v ) Also the approximate isosbectic point in S ( T, x ) as x is varied is reproduced by LDA+DMFT. ( vi ) Interestingly, S ( T ) We now describe our results. In Fig. 1, we show the resistivity, ρ$_{dc}$ ( T ) ≡ 1 /A$_{0}$ ( T ) in FeSe$_{1}$ − $_{x}$Te$_{x}$ , derived ear- lier [13]. It clearly shows the “S-like” shape character- istic of a PG metal. At low T , ρ$_{dc}$ ( T ) ≃ AT and the LFL-like T 2 form is never observed. With increasing x , ρ$_{dc}$ becomes more bad-metallic, smoothly going over to an insulator-like form up to very low T ≃ 2 . 0 K. In re- ality, at much higher T , either antiferromagnetic (AF) or unconventional superconducting (USC) transition will cut-off this extremely low crossover to a metal. For non AF/USC ordered systems, even a minute amount of non- magnetic disorder on FeSe layers (e.g, Cu [4] will imme- diately destroy metallicity, leading to a metal-insulator transition, as indeed seen in Fe$_{1}$ − $_{x}$Cu$_{x}$ Se for x << 1. Fo- cussing on x = 0 to make contact with experiment [10], Here, ρ$_{a}$ ( k , ω ) = − 1 $_{π}$Im 1 ω − Σ$_{a}$( ω ) − ϵ$_{k}$$_{,a}$ is the LDA+DMFT spectral function, a = ( xy, xz, yz, x 2 − y $^{2}$, 3 z 2 − r $^{2}$) rep- resent the five d orbitals, µ is the chemical potential, v$_{x,a}$ ( k ) is the group velocity, f ( ω ) is the Fermi-Dirac function and V the sample volume. In DMFT, the A$_{n}$ ( T ) are convertible to integrals over the unperturbed DOS. The only approximation made here is to ignore the k dependence of v$_{x,a}$ ( k ), i.e, v$_{x,a}$ ( k ) → v$_{x,a}$ = v . In an incoherent metal, such as we have here, this is justified, since, between successive hops, a carrier in an incoherent state does not exist long enough in a given k eigenstate. Another related reason is the bad-metallic resistivity, im- plying k$_{F}$ l ≃ O (1) and leading to the same conclusion. With this simplification, Eq. (3) for the intra-band con- tribution reads φ $^{xx}$( ω ) = v 2 V ∑ a $_{k}$ρ 2 $_{a}$( k , ω ). We now describe our results. In Fig. 1, we show the S ( T ) = 1 T A$_{1}$ ( T ) A$_{0}$ ( T ) , (1) k ( T ) = 1 T ( A$_{2}$ ( T ) − A 2 $_{1}$( T ) A$_{0}$ ( T ) ) , (2) φ $^{xx}$( ω ) = 1 V ∑ k T r [ v$_{x,a}$ ( k ) ρ$_{a}$ ( k , ω ) v$_{x,b}$ ( k ) ρ$_{b}$ ( k , ω )] . (3) with A$_{n}$ ( T ) = e 2 e n ℏ ∫ + ∞ −∞ dωφ $^{xx}$( ω )[ − f $^{′}$( ω )]( ω − µ ) n and FIG. 1: (Color online) Resistivity versus temperature (lower panel) and its derivatives (upper panel) showing their evolu- tion with increasing x ( n t = 6 + x ) within LDA+DMFT for fixed U = 4 . 0 eV and J H = 0 . 7 eV. The pseudogap scale is T PG ≃ 150 K (see text). 2 0 100 200 300 T (K) −2 0 2 4 d dc (T)/dT 0 100 200 300 T (K) −0.2 0.0 0.2 d 2 dc (T)/d 2 T 0 100 200 300 T(K) 0 500 1000 dc Ohm.cm) n$_{t}$=6.0 n$_{t}$=6.2 n$_{t}$=6.4 n$_{t}$=6.6