# [molpro-user] turning off dkroll

Kirk Peterson kipeters at wsu.edu
Fri Jun 13 07:16:18 BST 2008

```Hi Benj,

I think Ioannis suggestion will probably work. Note that there is a
bug in 2006.3 and 2006.4 (not sure if you are using the developer
versions) whereby the DK correction is not applied in 2nd and
subsequent iterations of a loop even though it says that it is being
done.

I would be a bit cautious with your basis set since these have been
contracted in non-relativistic calculations. In general one needs to
use basis sets that have been contracted in DK calculations (or
completely uncontract). Sets contracted for DK2 are available in the
Molpro library and are probably ok for Cl for higher order DK.

-Kirk

On Jun 13, 2008, at 12:45 AM, Benj FitzPatrick wrote:

> Hello,
> I was interested in seeing the effect of DKHO on the relativistic
> calculation
> and wanted to put this into a loop.  What do I need to do in order
> to compare
> these results with ones where I only compute one DKH energy in the
> job and run a
> lot of jobs?  Namely, I want to turn dkroll off (and dkroll=0
> doesn't appear to
> do it) b/c I have some preliminary HF calcs (some of the radicals
> I'll be
> studying don't converge unless I start with a small basis set) with
> smaller
> basis sets and I don't want them doing DKH calculations.  I gave a
> portion of
> the input file below.
> Thanks,
> Benj FitzPatrick
> University of Chicago
>
> basis=6-31G*;
> {hf;
> wf,40,1,0}
> basis=6-311G**;
> {hf;
> wf,40,1,0}
> basis,default=aug-cc-pvdz,cl=avdz+d;
> {hf;
> wf,40,1,0}
> eref1=energy
>
>
> dkhp=1
> i=0
> do dkhorder=2,6,1
> i=i+1
> !I need to turn off dkroll here
>
> basis=6-31G*;
> {hf;
> wf,40,1,0;
> start,atdens}
>
> basis=6-311G**;
> {hf;
> wf,40,1,0}
> dkroll=1
>
> basis,default=aug-cc-pvdz,cl=avdz+d;
> {hf;
> wf,40,1,0}
> dkho=dkhorder
> {hf;
> wf,40,1,0}
> enddo

```