Cross sections for electronic excitation of ${\mathrm{H}}_2$O by low-energy electrons have been studied using the Schwinger multichannel method. Differential and integral cross sections for excitation of the (3$a_1$→3${\mathrm{sa}}_1$${)}^3$$A_1$ dissociative state are reported for impact energies of 12, 15, and 20 eV. A comparison of the calculated integral cross sections with emission measurements for OH ($A^2$${\Sigma }^{+}$) produced via dissociative electron-impact excitation of ${\mathrm{H}}_2$O in this energy range is encouraging.

• Received 30 October 1989

DOI:https://doi.org/10.1103/PhysRevA.41.546