"Too many spin couplings" error message

[Peter Knowles]

I believe that you can edit src/common/cconf and
src/common/cconf1. You will need to recompile at least
src/mrci/{cicon,cilscc,cilsdm,cilsii,citrdm}.f
Good luck
Peter Knowles
Ioannis Kerkines wrote at 12:04 on 19 February 2001:
 > Dear list,
 > 
 > When I try to perform a rather large MRCI calculation on a diatomic
 > molecule, I get this error:
 > 
 > --------
 > 1PROGRAM * CI (Multireference internally contracted CI)     Authors: H.-J. Werner, P.J. Knowles, 1987
 > 
 > 
 >  Number of optimized states:  1  Roots:   1
 >  Number of reference states:  1  Roots:   1
 > 
 >  Reference symmetry:               4   Quartet
 >  Maximum shell in reference space  4
 >  Maximum shell inside CICON        7
 > 
 >  Maximum number of shells:             7
 >  Maximum number of spin couplings:  2002
 > 
 >  Reference space:     1857 conf     5008 CSFs
 >  N elec internal:   119030 conf   698336 CSFs
 >  N-1 el internal:   113401 conf  1276062 CSFs
 >  N-2 el internal:    46928 conf   865950 CSFs
 > 
 >  Number of electrons in valence space:                     17
 >  Maximum number of open shell orbitals in reference space:  9
 >  Maximum number of open shell orbitals in internal spaces: 15
 > 
 > 
 >  TOO MANY SPIN COUPLINGS:  2002 MXSPC=  1001
 > 
 >  ERROR EXIT
 > 
 > -------
 > 
 > Can I just, by intervening in the source code, change the MXSPC constant,
 > or this will create further problems?
 > 
 > Thanks in advance,
 > 
 > John Kerkines 
 > PhD Student
 > Laboratory of Physical Chemistry
 > Department of Chemistry
 > University of Athens, Greece
 > 

-- 
Prof. Peter J. Knowles              
Email P.J.Knowles at bham.ac.uk  Phone +44-121-414-7472  Fax +44-121-414-7471
School of Chemistry, Univ. of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
WWW http://www.tc.bham.ac.uk/~peterk/