 $CONTRL SCFTYP=RHF RUNTYP=RSURFACE NZVAR=18
 ICHARG=0 MULT=1 $END
 $STATPT NSTEP=200 $END
! TO USE GDIIS FOR GEOMETRY SEARCH (RECOMMENDED OPTION)
 $STATPT  METHOD=GDIIS $END
! TO ALLOW REGENERATION OF DLC EVERY 5 STEPS AS NEEDED AND/OR
! WHEN THEY BECOME BADLY DEFINED
 $STATPT  NOREG=5 $END
 $SURF NDISP1=50 DISP1=-0.025   IVEC1(1)=3,8 IGRP1(1)=8 ORIG1=0 $END
! TO REUSE APPROXIMATE HESSIAN INFORMATION DURING RELAXED SCANS
 $SURF REUSE=.T. $END
 $ZMAT DLC=.T. AUTO=.T. $END
! THE FOLLOWING OPTION IS REQUIRED FOR RELAXED SCANS IN DLC
 $ZMAT AUTOFV=.T. $END
! TO FREEZE DISTANCE BETWEEN FIRST AND SECOND ATOM
 $ZMAT IFZMAT(1)=1,3,8 $END
! EXPLICIT SPECIFICATION OF BOND 1-2
! JUST FOR THE CASE IF THE DISTANCE(S) WILL BECOME(S) TOO BIG
! TO BE SELECTED BY THE AUTOMATIC DLC GENERATOR DURING SCAN.
 $ZMAT NONVDW(1)=3,8 $END
 $BASIS  GBASIS=STO NGAUSS=3 $END
 $DATA
 C2H4O2
C1
CARBON      6.0      0.000000000         0.000000000         0.000000000
CARBON      6.0      0.000000000         0.000000000         1.536800000
OXYGEN      8.0      0.973776000         0.000000000        -0.728798000
OXYGEN      8.0     -1.295983000         0.000000000        -0.507480000
HYDROGEN    1.0      1.021154000         0.000000000         1.903500000
HYDROGEN    1.0     -0.517652000         0.881552000         1.904452000
HYDROGEN    1.0     -0.517652000        -0.881552000         1.904452000
HYDROGEN    1.0     -1.178501000         0.000000000        -1.490541000
 $END