Conical intersection opt

CASSCF

#----------------------------------------------------------------------
# Gradient projection method for CI between S1 and S2 by SA3-CASSCF(4,4)/6-31G
#

$COMPASS 
Title
 C2H4 Molecule test run
Basis
 6-31G
Geometry
C            -0.15706002      0.00190775      0.83652009
C             0.15008784     -0.00133762     -0.83154671
H             0.03427061     -0.96458044      1.25530646
H             0.06498491      0.96390175      1.24999388
H            -0.05275481      0.96366210     -1.24919243
H            -0.03963123     -0.96356671     -1.26123252
END geometry
nosym
$END

$bdfopt
iprt
 3
imulti
 1
tolgrad
1.d-3
tolene
1.d-5
$end

$xuanyuan
$end

$SCF
RHF
charge
 0
spin
 1
atomorb
$END

%cp $BDF_WORKDIR/$BDFTASK.scforb $BDF_WORKDIR/$BDFTASK.inporb

$expandmo
vcmo
occao
2 2
minbas
4
1C|2P-1  
1C|2P0   
2C|2P-1   
2C|2P0   
$end

%cp $BDF_WORKDIR/$BDFTASK.exporb $BDF_WORKDIR/$BDFTASK.inporb

$mcscf
close
6
active
4
actele
4
spin
1
roots
3 3 1
symmetry
1
guess
read
molden
quasi
icas
$end

$grad
nrootgrad                                                                      
2 
double
maxiter
500
mxiter
50
cutcpmc
1.d-5
$end

$grad
nrootgrad                                                                      
3 
double
maxiter
500
mxiter
50
cutcpmc
1.d-5
$end