Some remarks on the resemblance theorems associated with various orthonormalization procedures
Per‐Olov Löwdin · International Journal of Quantum Chemistry · 1993
Abstract A survey is given of the resemblance theorems associated with various types of orthonormalization procedures having different kinds of symmetry properties appearing in the current literature. It is shown that the proofs for the minimum properties are closely connected with the fact that the Hilbert–Schmidt norm of an operator is always nonnegative and has the lowest value equal to zero. © 1993 John Wiley & Sons, Inc.