[molpro-user] Linear dependent basis

[John Keith]

AHA!  I can now see how that would cause serious problems and I'm
lucky you caught this. I had used Cartesian functions to have
continuity with earlier Pople basis set calculations I ran with
Jaguar, the program I have the most experience with.  Lesson learned.

I'll make this change and then write a follow-up if that resolved my
linear dependency problem.

Many thanks,

--john


On Mon, Jul 12, 2010 at 5:52 PM, Kirk Peterson <kipeters at wsu.edu> wrote:
> John,
>
> I just now noticed you are using cartesian polarization functions. All correlation consistent basis sets
> use pure spherical harmonics.  Use of cartesians will certainly give you linear dependency problems
> due to the extra functions this adds. This should not be done!  You were just lucky this didn't happen
> earlier.
>
> regards,
>
> Kirk
>
>
> On Jul 12, 2010, at 3:11 AM, John Keith wrote:
>
>> Hi all,
>>
>> I'm trying to run single reference ab initio calculations on
>> transition metal complexes and build up enough calculations to
>> extrapolate to the CBS limit.
>>
>> My molecule is the PdCl4 dianion, and I'm using the Stuttgart Pd
>> pseudopotential and the (aug)-cc-pvNZ basis sets on all other valence
>> electrons. All are taken from the EMSL basis set library. I get SCF
>> convergence with cc-pvDZ, aug-cc-pvDZ, cc-pvTZ, and aug-cc-pvTZ basis
>> sets, but at cc-pvQZ I run into an error saying:
>>
>> ------------------------
>> Eigenvalues of metric
>>
>>         1 0.212E-08 0.406E-05 0.681E-05 0.681E-05 0.835E-05 0.102E-04
>> 0.103E-04 0.106E-04
>>
>> ERROR: BASIS LINEARLY DEPENDENT OR WRONG S
>>
>> The current threshold for the smallest tolerated eigenvalue of S is   1.0D-08
>> ------------------------
>>
>> I spent some time searching the user-list and google, and I couldn't
>> find a solution I needed.  What I gather is that since my geometries
>> are reasonable, the jobs run fine with smaller basis sets, and since I
>> only have one eigenvalue below the threshold, this error probably just
>> comes from the fact my QZ basis is (not surprisingly) linearly
>> dependent and should be scaled down one or a few basis functions.
>>
>> Pardon the naive question, but does someone know the "right" way to
>> modify this basis set so it is not linearly dependent, but that it is
>> also of desired quality for a meaningful CBS extrapolation? Is it as
>> straightforward as starting at the QZ basis and removing individual
>> diffuse functions until the basis set is not linearly dependent, or is
>> there a higher art to it?
>>
>> My input file is:
>> ***Pd_4Cl
>>
>> cartesian
>>
>> geomtyp=xyz
>> orient,mass
>> geometry={
>> 5
>> Pd_4Cl calc
>> Pd   -0.213992    0.027380   -0.117721
>> Cl   -1.943705   -1.515957    0.437439
>> Cl    1.304488   -1.784426   -0.423439
>> Cl    1.515859    1.570547   -0.672946
>> Cl   -1.732472    1.839247    0.188003
>> }
>> set,charge=-2
>>
>> <BASIS>
>>
>> hf
>>
>> In my <BASIS> block, I've been using a script to pasting the explicit
>> basis sets from the EMSL website into the input file. I don't want to
>> paste all those messy numbers here unless that's actually requested.
>>
>> Thanks in advance!
>>
>> --john
>>
>> #####################################################################
>> Ph D. John A. Keith
>> Institut für Elektrochemie     Email: john.keith at uni-ulm.de
>> Universität Ulm                    Telephone: +49-731-50-26061
>> Albert-Einstein-Allee 47       URL: http://www.wag.caltech.edu/home/johnk
>> Ulm D-89069                       URL:
>> http://www.uni-ulm.de/theo_echem/index.shtml
>> #####################################################################
>> There is as much difference between us and ourselves as between us and others.
>>
>> -Michel de Montaigne, essayist (1533-1592)
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>
>



-- 
#####################################################################
Ph D. John A. Keith
Institut für Elektrochemie     Email: john.keith at uni-ulm.de
Universität Ulm                    Telephone: +49-731-50-26061
Albert-Einstein-Allee 47       URL: http://www.wag.caltech.edu/home/johnk
Ulm D-89069                       URL:
http://www.uni-ulm.de/theo_echem/index.shtml
#####################################################################
There is as much difference between us and ourselves as between us and others.

-Michel de Montaigne, essayist (1533-1592)
#####################################################################