Deformation potentials associated with the conduction band edge in Si are calculated using a pseudo-potential rigid ion model and the results of the band structure calculation made by Kleinman and Phillips in 1960. This simple method should give a good estimate for Θ_u, the shear component, but not necessarily for Θ_d. The calculated value of Θ_u, 8.4±0.3 eV, agrees well with experiment but there is no agreement for Θ_d.