$CCHEMRI group (optional, relevant if CODE=RICCHEM in $MP2)
 
   This group controls how the RI-MP2/RI-ZAPT energy
and RI-MP2 gradient are performed.
 
IAUXBF = 0 uses Cartesian Gaussians
       = 1 uses spherical harmonics
           for the auxiliary basis set used to expand the
           MP2 energy expression into products of 3-index
           matrices.  The default is inherited from ISPHER
 
The following options are for the RI-MP2 gradient only:
 
INVCUT = specifies which eigenvectors from the two-
         center ERI matrix are used to constuct the
         inverted Coulomb metric (default 10).
	 Eigenvectors with eigenvalues that have a
         magnitude less than INVCUT
         are not used to contruct the Coulomb metric.
	 Decreasing INVCUT(e.g. INVCUT=7) can help with
         numerical issues.
 
IRTCUT = specifies which eigenvectors from the block
         diagonal relaxed two-particle density matrix
         are used to contruct the square root of said
         matrix. Eigenvectors with eigenvalues that have
         a magnitude less than IRTCUT
         are not used to contruct the matrix root.
         This matrix is used to construct part of
         the lagrangian matrix (default 10).