! EXAM 12.
!   This job illustrates linear bends, for acetylene, and
!   tests the closed shell LDA density functional program.
!
!   At the input geometry,
!   the FINAL E= -76.5352334525 after 15 iterations,
!   and the RMS gradient is 0.0944557.
!
!   At the optimized geometry, 5 steps later,
!   the FINAL E= -76.5841347569, RMS gradient=0.0000007,
!   R(CC)=1.21193 and R(CH)=1.07797.
!
 $CONTRL SCFTYP=RHF DFTTYP=SVWN RUNTYP=OPTIMIZE NZVAR=5 $END
 $SYSTEM TIMLIM=3 $END
 $BASIS  GBASIS=N31 NGAUSS=6 NDFUNC=1 $END
 $GUESS  GUESS=HUCKEL $END
!   Note, this OPTTOL is smaller than the accuracy of the
!   integration grid actually supports (see REFS.DOC)
 $STATPT OPTTOL=0.00001 $END
 $DATA
Acetylene geometry optimization in internal coordinates
Dnh      4

CARBON      6.0    0.0  0.0  0.70
HYDROGEN    1.0    0.0  0.0  1.78
 $END
 $ZMAT  IZMAT(1)=1,1,2,   1,1,3,   1,2,4,
                 5,1,2,4,    5,2,1,3  $END
------- XZ is 1st plane for both bends -------
 $LIBE  APTS(1)=1.0,0.0,0.0,1.0,0.0,0.0 $END