  Current standard solar models neither account properly for the photospheric
lithium abundance nor reproduce the inferred solar sound speed profile.
Diffusive overshooting at the base of the solar convective envelope has
previously been shown to solve either of these model inadequacies. In this
paper, we present an analysis of solar models with four different
parametrizations of diffusive overshooting. We find that these models are able
to recover the correct lithium depletion, regardless of the parametrization, if
overshooting is suppressed, during the early evolutionary stages. Further,
parametrizations of diffusive overshooting have been shown to improve the
inferred sound speed profile. However, none of the presented models are able to
simultaneously solve both model inadequacies, showing that diffusive
overshooting on its own is deficient to account for observations.
