:set">5.7</A>.  If this basis set is not defined by input,
the <IMG
 WIDTH="51" HEIGHT="33" ALIGN="MIDDLE" BORDER="0"
 SRC="img106.gif"
 ALT="$O(N^4)$"> exact Coulomb contribution is computed.

<P>
The user also has the option of specifying a third basis set for the 
evaluation of the exchange-correlation potential.  This basis set must
have the name <TT>"xc basis"</TT>.  If this basis set is not specified
by input, the exchange contribution (XC) is evaluated by numerical
quadrature.  In most applications, 