# CCL:G: problem about casscf calculation

*From*: "Zijun Yu" <zjyu:lamar.colostate.edu>
*Subject*: CCL:G: problem about casscf calculation
*Date*: Tue, 30 Nov 2010 17:33:20 -0500

Sent to CCL by: "Zijun Yu" [zjyu||lamar.colostate.edu]
Hi All,
I perform a CASSCF(14,11) calculation to serach the conical intersection.
My input file is as below:
%chk=NM.chk
%mem=4000MB
%nprocshared=4
# casscf(14,11,nroot=2)/6-31g(d) guess=read pop=full gfinput nosymm
scf=(maxcycle=900) opt=(conical,maxcycle=500)
output file:
Total number of active electrons 14
Total number of active orbitals 11
Number of Alpha electrons 7
Number of Beta electrons 7
IEnd,MeIgot for IE vector 7 7
Number of Alpha strings 330
Number of Beta strings 330
Number of configurations 54615
SME calculated on fly
RWF file will be 16 Words long
Len28= 16 LenMCI= 30.
MCSCF will prepare Gradient Dif. and Deriv. Cps.
Enter MCSCF program.
NO. OF ORBITALS = 66 NO. OF CORE-ORBITALS = 9
NO. OF VALENCE-ORBITALS = 11 NO. OF VIRTUAL-ORBITALS = 46
USED ACCURACY IN CHECKING CONVEGERGENCE = 1.00D-08
Memory needed for Incore Integrals: 7148394
Memory needed for direct integral evaluation: 4634616
Integrals KEPT IN MEMORY
IBUJAK length= 1845591
Integral file not found: evaluate integrals
Symmetry not used in FoFDir.
MinBra= 0 MaxBra= 2 Meth= 1.
IRaf= 0 NMat= 1 IRICut= 1 DoRegI=T DoRafI=F ISym2E= 0 JSym2E=0.
First order MCSCF but last itn is Quadratic
GetSCM: Allocation for REFSC failed:
Core=46912516321296 Need=4476969654 GauSpace=46912516321296 MaxMem=524288000
Avail=524288000.
Error termination via Lnk1e in /usr/apps/chemistry/gaussian/g03/g03/l510.exe at
Tue Nov 30 12:43:52 2010.
Job cpu time: 0 days 0 hours 0 minutes 14.6 seconds.
File lengths (MBytes): RWF= 43 Int= 0 D2E= 0 Chk= 10 Scr= 1
Does it mean that the mem is not eough? Or how much mem I should allocate?
Thanks a lot
Zijun Yu
Department of chemistry
Colorado State university
Fort Collins, CO