We present the results of determination of the barium abundance considering the non-LTE ( NLTE ) effects in 172 dwarf stars in the metallicity range of –1 < [ Fe/H ] < +0.3 , assigned to different Galactic substructures by kinematic criteria .
We used a model of the Ba atom with 31 levels of Ba i and 101 levels of Ba ii .
The atmosphere models for the investigated stars were computed using the ATLAS9 code modified by new opacity distribution functions by Castelli & Kurucz ( 13 ) .
The NLTE profiles of the unblended Ba ii ( 4554Â Ã , 5853Â Ã , 6496Â Ã ) were computed and then compared to those observed .
The line 6141Â Ã Â was also used , but with an allowance for its correlation with the iron line .
The average barium abundances in the thin and thick discs are 0.01 \pm 0.08 and –0.03 \pm 0.07 , respectively .
The comparison to the calculations of the Galactic chemical evolution by ( 46 ) was conducted .
The trend obtained for the Ba abundance versus [ Fe/H ] suggests a complex barium production process in the thin and thick discs .