Comment on "Extreme lowering of the Debye temperature of Sn nanoclusters embedded in thermally grown SiO2 by low-lying vibrational surface modes"

This Comment corrects two separate errors which previously appeared in the calculation of vibrational mode frequencies of tin spheres embedded in a silica matrix. The first error has to do with the vibrational frequency of a free elastic sphere. The second error has to do with the effect on the vibrational frequencies of a sphere due to its embedding in an infinite elastic matrix.