Too Many Active Orbitals?
P.J.Knowles at bham.ac.uk
Wed Jul 2 17:45:41 BST 2003
Yes, the number of closed+active (mrci, rs2) or active (mcscf, rs2c)
orbitals can be at most half of the number of bits in an integer
(integers are used to store patterns with 2 bits per active
orbital). Apologies that this is not clearly stated in the manual.
At 02 Jul 2003 10:33:47 -0600,
Matt Thompson wrote:
> [1 <text/plain (quoted-printable)>]
> I hope this isn't a FAQ, but I couldn't find the answer anywhere. I am
> trying to do a calculation that has succeeded before on 2002.3, but now
> fails on 2002.6. The job stops with:
> TOO MANY ACTIVE ORBITALS: 22 THIS VERSION ALLOWS 16
> I tracked this to src/mrci/ciinit.f, but I'm not sure on how to increase
> this. Is it one of those options in the configure process, or do I need
> to hack a common? If the hack, is it safe to do? Or is it a 32-bit
> limit (see below)?
> I am also puzzled why this job did work on .3 and not .6. Could this be
> due to .6 being on a 32-bit system (dual Xeon with 4 GB of memory) and
> the .3 on a 64-bit system (Alpha with 768 MB)? If so, are there other
> parameters I need to watch out for that kill on 32-bit?
> Thanks for any help,
> Matt Thompson
> "And isn't sanity really just a one-trick pony, anyway? I mean,
> all you get is one trick, rational thinking, but when you're good
> and crazy, ooh ooh ooh, the sky's the limit!" -- The Tick
> The Matt -- http://ucsub.colorado.edu/~thompsma/
> [2 This is a digitally signed message part <application/pgp-signature (7bit)>]
Prof. Peter J. Knowles
Email P.J.Knowles at bham.ac.uk Phone +44-121-414-7472 Fax +44-121-414-7471
School of Chemical Sciences, University of Birmingham, Birmingham, B15 2TT, UK
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