Se analiza una aplicación del principio variacional de Schwinger desde la perspectiva de ondas planas para un conjunto base usando un modelo Born-Ochkur. El propósito de este trabajo es mostrar la sección eficaz para e‾ - H2O en el intervalo de 10 - 50 eV. Los resultados se comparamos con los experimentos.We report an application of the Schwinger variational principle with plane waves as a trial basis set. Differential cross sections are obtained for e‾- H2O from 10 to 50 eV. In these studies the exchange potential is evaluated by the Born-Ochkur model and our results are found to be in reasonable agreement with experimental data and theoretical studies.