Calculation of molecular line intensity in stellar atmospheres

Molecular line intensity calculations are not a straightforward task. We present a description of the basics for including molecular lines in synthetic spectra and of the input data needed. We aim both at describing ways in which molecular lines are computed in the context of photospheres of F-G-K stars, and to present a new online available version of our code for spectrum synthesis of cool stars. We apply calculations to molecular bands in the ultraviolet, visible, and near-infrared main features, and comparisons with spectra of reference stars are shown. We provide user-friendly tools for the free use of the code Pfant. The code is available at <uri xlink:href="http://trevisanj.github.io/PFANT" xlink:type="simple">http://trevisanj.github.io/PFANT</uri>.