Electronic excitation ofH2O by low-energy electron impact

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.