\begin{table}%T4
\caption{\label{t_species}Overview of dust species used in our fitting routines.}
\small%\centerline
{                      
 \begin{tabular}{llll}
\hline\hline
\noalign{\smallskip}
Species & State$^a$ 
& Chemical & Shape\\
        &       & formula  &       \\ 
\hline
\noalign{\smallskip}
Amorphous silicate$^{1}$  & A  &  MgFeSiO$_{4}$       & Homogeneous \\
(Olivine stoichiometry)& &                      &     Sphere          \\
Amorphous silicate$^{1}$  & A  &  MgFeSi$_{2}$O$_{6}$ & Homogeneous \\
(Pyroxene stoichiometry)&                      &             & Sphere  \\
Forsterite$^{2}$   & C  &  Mg$_{2}$SiO$_{4}$   & Hollow  Sphere    \\
Clino Enstatite$^{3}$& C  &  MgSiO$_{3}$         & Hollow  Sphere    \\
Silica$^{4}$     & A  &  SiO$_{2}$           & Hollow  Sphere    \\ 
\hline
\end{tabular}}
 \smallskip
References: (1) Dorschner et~al. \ (\cite{dorschner1995});
  (2) Servoin et~al.\ (\cite{servoin1973});  (3)~J\"ager et~al.\ (\cite{jaeger1998}); (4) Henning et~al.   (\cite{henning1997}).\\
 $^a$  Lattice structure: Amorphous (A) or Crystalline (C).
\end{table}