148. popt, readopt and g09?

Update:
NOTE that readopt WORKS in G09 rev. B and rev. D. It DOESN'T work in G09 rev. A.

readopt is a whole lot easier to use than popt.

Original post:
For various reasons I want to be able to freeze some atoms while including other in my optimisation using gaussion 09. Readopt (http://www.gaussian.com/g_tech/g_ur/k_opt.htm) sounded like a good idea.

The problem
I can't get this to work:

%nprocshared=6
%Chk=reduced_solvate.chk
#P ub3lyp/lanl2dz 6D 10F opt=ReadOptimize Punch=(MO) Pop=() 

reduced_solvate

3 2 ! charge and multiplicity
 Cr     10.0000     10.0000     10.1100
 O     10.0000     10.0000     12.1300
 H     10.0000     10.8000     12.7000
 H     10.0000     9.20000     12.7000
 O     10.0000     7.84000     10.0000
 H     10.0000     7.15000     10.6900
[..]
 H     6.32536     3.63314     12.3506
 H     8.48233     15.9732     5.80567

noatoms atoms=1-19

readopt and rdopt don't work either -- they all give 'syntax error' (C64 flashback!)

 QPErr --- A syntax error was detected in the input line.
 #P ub3lyp/lanl2dz 6D 10F ReadOptimize Pu
                                                  '
 Last state="GCL"

The solution: 

I didn't come up with this: http://ccl.net/cgi-bin/ccl/message-new?2012+04+24+002+raw

Anyway, you can use popt but it takes a bit more preparation of the coordinates.

You can convert an .xyz file quickly by using:

cat molecule.xyz | gawk '{print $1,"-1",$2,$3,$4}'>popt_molecule.xyz

Change 0 to -1 for the atoms you want to optimise.

%nprocshared=6
%Chk=popt_solvate.chk
#Popt ub3lyp/lanl2dz 6D 10F Punch=(MO) scf=(maxcycle=1024)

reduced_solvate popt

3 2 ! charge and multiplicity
Cr 0 10.0000 10.0000 10.1100
O 0 10.0000 10.0000 12.1300
H 0 10.0000 10.8000 12.7000
H 0 10.0000 9.20000 12.7000
O 0 10.0000 7.84000 10.0000
H 0 10.0000 7.15000 10.6900
[..]
H -1 3.62686 7.14993 12.8142
H -1 5.12696 15.5239 9.01700
H -1 6.32536 3.63314 12.3506
H -1 8.48233 15.9732 5.80567