[molpro-user] Too many active orbitals

[Matt Thompson]

On Thu, 2004-05-06 at 09:32, John S. Sears wrote:
> I'm trying to run some large MCSCF/MRCI calculations and I am getting the
> following error inside multi.  Is there a key word that I need to change
> to set the maximum number of active orbitals?  Thanks in advance for your
> help.
> Best wishes
> John
> 
> Here's the error
> 
>  Convergence thresholds  0.10E-01 (gradient)  0.10E-05 (energy)  0.10E-02
> (step length)
>  ? Error
>  ? Too many active orbitals
>  ? The problem occurs in muinpw
> 
>  ERROR EXIT
>  CURRENT STACK:      MAIN

Molpro is limited to a number of active orbitals half the "bit size" of
your processor.  So, if you are on a Xeon, which is a 32-bit processor,
you can have at most 16 active orbitals.  If you need more, you need to
use a 64-bit processor like an Alpha, which can handle 32.

I ran into this a while back while moving from an Alpha that I do most
of my work on to a Xeon cluster.  It is as hard-coded a limit on Molpro
as you will find.

Matt

-- 
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   Matt Thompson -- http://ucsub.colorado.edu/~thompsma/
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