[molpro-user] Help with SLAPAF Program

[Alexander Mitrushchenkov]

Dear Angelo.

In your input constraints are missing! Only primitive is defined, but 
constraint itself not. You should read more carefully the manual.
If you want to constraint C1-C4 bond to say $rcc, there should be something 
like:

primitive,b1,bond,atoms=[C1,C4];
constraint,$rcc,b1;

or simply


constraint,$rcc,bond,atoms=[C1,C4];


Moreover, the output you've attached, was empty.

Best wishes,

Sasha



On Thursday 31 January 2008 02:41, you wrote:
> Dear Sasha:
>
> Thank you so much for your quick response.
>
> But, the constraints are not working for me.
>
> Here is my input file.  I don't think it can get much simpler.
>
> *** bicyclobutane - ground state
> memory,128,m
>
> FILE,2,./wfu/test_constraint.wfu,new
>
> geomtyp=xyz
> geometry={
> ANGSTROM
> 10
> Bicyclobutane
> C1          6.0  -0.8464354380  -0.1961899345   0.2856934463
> C2          6.0   0.8464354380   0.1961899345   0.2856934463
> C3          6.0   0.1359364305   1.4453100675  -0.2977645687
> C4          6.0  -0.1359364305  -1.4453100675  -0.2977645687
> H1          1.0  -1.3189804253  -0.2580074160   1.2491001668
> H2          1.0   1.3189804253   0.2580074160   1.2491001668
> H3          1.0   0.1708354934   1.5903287379  -1.3664594314
> H4          1.0  -0.1708354934  -1.5903287379  -1.3664594314
> H5          1.0   0.1455613584   2.3655897131   0.2610880557
> H6          1.0  -0.1455613584  -2.3655897131   0.2610880557
> }
>
> basis=sto-3g
>
> rcc=1.50;
>
> hf
>
> {optg,method=slrf
> ! constraint,0,bond,atoms=[C1,C4],-1.,bond,atoms=[C2,C3]
> ! constraint,$rcc,angstrom,bond,atoms=[C1,C2]
> primitive,b1,bond,atoms=[C1,C4];
> }
>
> put,molden,test_constraint.molden;
> ---
>
> Here is what I am trying to do:
>
> If one views the bicyclobutane from above, it appears as a parallelogram
> with an additional bond across the diagonal.
>
> The intent is to obtain a relaxed potential energy curve for the opening of
> two bonds that are opposite each other (See a and b below.), as one
> gradually stretches them.  It requires two constraints, one for a and one
> for b; and they will be held fixed for each point on the curve while all
> other coordinates are varied.
>
>
>
>                            /\a                   ||
>                           /  \                   ||
>                           ----        --->       ------
>                           \  /                        ||
>                          b \/                         ||
>
>                        bicyclobutane            butadiene
>
>
> The bonds a, b are to be constrained to a series of values:
> 1.5,1.6,1.7,1.8,1.9,2.0 .
>
> By the time the a and b bonds reach 2.0, then butadiene is well on its way
> to being formed (incipient butadiene).
>
> None of the constraints work.
>
> 1) Both forms of the constraint command give me an error.
>
> 2) molpro doesn't recognize the primitive command.
>
> I have attached the output from molpro.
>
> Please help.
>
> Regards,
>
> Angelo

-- 
-----------------------------------------
Dr. Alexander Mitrushchenkov, IGR
Université Paris-Est
Laboratoire de Chimie Théorique, EA2180
5 bd Descartes, Champs-sur-Marne,
77454 Marne la Vallée Cedex 2 France

Phone:    +33(0)160957316
Fax:      +33(0)160957320
e-mail:   Alexander.Mitrushchenkov at univ-mlv.fr
-----------------------------------------