We have restructured the SCF code to rephrase as much linear
algebra as possible as matrix multiplication operations.  Most novel
is the new matrix exponentiation routine that provides an accurate
unitary approximation, which eliminates the necessity of
orthogonalization and stabilizes the initial search step when large
rotations are applied.  The new matrix exponentiation algorithm (a
modification of one due to Moler) is
<OL>
  <LI> scale the matrix by a power of two so the largest element is less
       t