Cool Stars 14 - Submitted Abstract # 63 This version created on 05 October 2006 Modeling molecular polarization from starspots Nadine Afram, ETH Zurich Svetlana Berdyugina, ETH Zurich Dominique Fluri, ETH Zurich Felix Suwald, ETH Zurich Jeff Kuhn, University of Hawaii Dave Harrington, University of Hawaii For cool stars with magnetic activity we have analyzed the usefulness of molecules as a diagnostic tool for direct measurement of magnetic fields with the molecular Zeeman and Paschen-Back effects in spatially unresolved starspots. We present calculated molecular line profiles for MgH, TiO, CaH, and FeH to investigate the temperature range in which the selected molecules can serve as indicators for magnetic fields. In a next step we compare the synthetic Stokes profiles with our recent observations (ESpADOnS, CFHT) of G-K-M stars with surface magnetic fields producing LSD Stokes V signals in atomic lines and circular polarization in some molecular lines. ----------------------------------