  We present high accuracy relativistic coupled cluster calculations of the
P-odd interaction coefficient $W_A$ describing the nuclear anapole moment
effect on the molecular electronic structure. The molecule under study, BaF, is
considered a promising candidate for the measurement of the nuclear anapole
moment, and the preparation for the experiment is now underway [Altunas et al.,
Phys. Rev. Lett. 120, 142501 (2018)]. Influence of various computational
parameters (size of the basis set, treatment of relativistic effects, and
treatment of electron correlation) on the calculated $W_A$ coefficient is
investigated and a recommended value of 147.7 Hz with an estimated uncertainty
of 1.5% is proposed.
