Fine-structure excitation of Fe⁺ due to collisions with H

Calculations of rate coefficients for fine-structure excitation within the ground term of Fe⁺(⁶D) due to collisions with atomic hydrogen are presented. The results are obtained with a molecular- orbital close-coupling method using FeH⁺ potential energies computed with the multireference single- and double-excitation configuration interaction method. The rate coefficients are compared to model predictions from the empirical model of Bahcall and Wolf and to electron-impact excitation for temperatures from 10 to 1000 K. Astrophysical applications of the fine-structure excitation rate coefficients are briefly discussed including predictions of the critical density and non-LTE infrared emission modeling. This work was partially supported by NASA grant NNX1SAE47G.