$TRUDGE group (optional, required for RUNTYP=TRUDGE)

This group defines the parameters for a non-gradient optimization of exponents or the geometry. The TRUDGE package is a modified version of the same code from Michel Dupuis' HONDO 7.0 system, originally written by H.F.King. Presently the program allows for the optimization of 10 parameters.
Exponent optimization works only for uncontracted primitives, without enforcing any constraints. Two non-symmetry equivalent H atoms would have their p function exponents optimized separately, and so would two symmetry
equivalent atoms! A clear case of GIGO.
Geometry optimization works only in HINT internal coordinates (see $CONTRL and $DATA groups). The total energy of all types of SCF wavefunctions can be optimized, although this would be extremely stupid as gradient methods are far more efficient. The main utility is for open shell MP2 or CI geometry optimizations, which may not be done in any other way with GAMESS. If your run requires NOSYM=1 in $CONTRL, you must be sure to use only C1 symmetry in the $DATA group.
OPTMIZ = a flag to select optimization of either geometry or exponents of primitive gaussian functions.
               = BASIS for basis set optimization.
               = GEOMETRY for geometry optimization (default). This means minima search only, there is no saddle
                  point capability.
NPAR = number of parameters to be optimized.
IEX = defines the parameters to be optimized.
If OPTMIZ=BASIS, IEX declares the serial number of the Gaussian primitives for which the exponents will be optimized (von welcher Gaußfunktion).
If OPTMIZ=GEOMETRY, IEX define the pointers to the HINT internal coordinates which will be optimized. (Note that not all internal coordinates have to be optimized.) The pointers to the internal coordinates are defined as: (the number of atom on the input list)*10 + (the number of internal coordinate for that atom). For each atom, the HINT internal coordinates are numbered as 1, 2, and 3 for BOND, ALPHA, and BETA, respectively.
P = Defines the initial values of the parameters to be optimized. You can use this to reset values given in $DATA. If omitted, the $DATA values are used. If given here, geometric data must be in Angstroms and degrees.
A complete example is a TCSCF multireference 6-31G geometry optimization for methylene,
$CONTRL SCFTYP=GVB CITYP=GUGA RUNTYP=TRUDGE COORD=HINT $END
$BASIS GBASIS=N31 NGAUSS=6 $END
$DATA
Methylene TCSCF+CISD geometry optimization
Cnv 2
C 6. LC 0.00 0.0 0.00 - O K
H 1. PCC 1.00 53. 0.00 + O K I
$END
$SCF NCO=3 NPAIR=1 $END
$TRUDGE OPTMIZ=GEOMETRY NPAR=2
IEX(1)=21,22 P(1)=1.08 $END
$CIDRT GROUP=C2V SOCI=.TRUE. NFZC=1 NDOC=3 NVAL=1
NEXT=-1 $END

using GVB-PP(1), or TCSCF orbitals in the CI. The starting bond length is reset to 1.09, while the initial angle will be 106 (twice 53). Result after 17 steps is R=1.1283056, half-angle=51.83377, with a CI energy of
-38.9407538472
Note that you may optimize the geometry for an excited CI state, just specify 
$GUGDIA NSTATE=5 $END
$GUGDM IROOT=3 $END
to find the equilibrium geometry of the third state (of five total states) of the symmetry implied by your $CIDRT.