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= bdfopt =

See source/bdfopt, module/dlfind_module.F90, sys_util/bdf_dlfind_util.F90 for interface.

<<TableOfContents(4)>>

{{{
Geometry optimiser of BDF package. This module can be used to find minimal points, saddle points and also conical intersection points. 
}}}


== Current limitations ==

1. Change of symmetry during optimization is not correctly handled for excited state optimization, because the correct input file needs to be prepared.

== Examples ==

=== Ground-state opt ===

{{{

$COMPASS    
Title
 CH2 Molecule test run, cc-pvqz
Basis
 3-21g
# cc-pvdz
Geometry
O       0.00000000     -0.00000000      0.00174418
H      -0.78045951      0.00000000     -0.10962269
H       0.78045951      0.00000000     -0.10962269
End geometry
Check
Skeleton
$END

$bdfopt
$end

$XUANYUAN
$END

$SCF
RHF
$END

$resp
geom
norder
1
method
1
$end

}}}

=== Excited state opt ===

{{{

$COMPASS    
Title
 CH2 Molecule test run, cc-pvqz
Basis
 3-21g
Geometry
 O  0.000000    0.000000    0.243991
 H  0.000000    1.178727   -0.45964
 H  0.000000   -1.178727   -0.45964
End geometry
Check
Skeleton
$END

$bdfopt
$end

$XUANYUAN
$END

$SCF
RHF
$END

$tddft
imethod
1
itda
0
idiag
1
istore
1
iexit
1
crit_e
1.d-8
crit_vec
1.d-6
$end

$resp
geom
norder
1
method
2
states
1
1 4 1
nfiles
1
$end

}}}

== General keywords ==
=== Maxcycle ===
{{{#!wiki
xxx
}}}
=== Method ===
{{{#!wiki
xxx
}}}