FUNCTION dustem_define_dustem_data,polarization=polarization,rchi2_weight=rchi2_weight

if keyword_set(polarization) then begin
    dustem_data_st ={    $ ;Structure contaning the data to fit
                                sed:    ptr_new(),      $ ; 
                                ext:    ptr_new(),      $ ;
                                qsed: ptr_new(),        $ ; 
                                used: ptr_new(),        $ ; 
                                polsed: ptr_new(),      $ ; 
                                polfrac: ptr_new(),     $ ;   
                                psi_em: ptr_new(),      $ ; 
                                qext: ptr_new(),        $ ; 
                                uext: ptr_new(),        $ ;
                                polext: ptr_new(),      $ ;
                                fpolext: ptr_new(),     $ ;  
                                psi_ext: ptr_new()      $ ; 
                                 
                         }
    rchi2_weight = {sed: 0.,ext: 0.,qsed:0.,used:0.,polsed:0.,polfrac:0.,psi_em:0.,qext:0.,uext:0.,polext:0.,psi_ext:0.}
         
endif else begin
    dustem_data_st = {    $ 
                                sed:    ptr_new(),      $
                                ext:    ptr_new()       $
                         }
	    rchi2_weight = {sed: 0.,ext: 0.}
endelse

RETURN,dustem_data_st

END