Rotational excitation of asymmetric-top molecular ions by electron impact: application to H${}_2$O${}^{+}$, HDO${}^{+}$, and D${}_2$O${}^{+}$

The rotational excitation of the three asymmetric-top molecular ion isotopologues H${}_2$O${}^{+}$, HDO${}^{+}$, and D${}_2$O${}^{+}$ is studied theoretically using a combined framework of electron-molecule R-matrix scattering theory, multichannel quantum-defect theory, frame transformation theory, and the Coulomb-Born approximation. The latter two have been adapted here for asymmetric-top rotors. State-resolved cross sections and kinetic rate coefficients for transitions from the rotational ground state of the ions are presented. State-resolved rate coefficients for all calculated transitions $N=0\text{ldotstwo}4$ are included as supplementary material and will be made available through the EMAA database.