EN
For a completely non-unitary contraction T, some necessary (and, in certain cases, sufficient) conditions are found for the range of the $H^{∞}$ calculus, $H^{∞}(T)$, and the commutant, {T}', to contain non-zero compact operators, and for the finite rank operators of {T}' to be dense in the set of compact operators of {T}'. A sufficient condition is given for {T}' to contain non-zero operators from the Schatten-von Neumann classes $S_{p}$.