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** Memory problem of XMCQDPT2 **
Panwang Zhou

pwzhou@gmail.com

Dear all,When performing the XMCQDPT2 calculation I encountered the following problem：

the job exited at the "ROUTINE MQCACI" and the error information is related to the memory usage:

********** ROUTINE MQCACI **********************************************

***** ERROR: MEMORY REQUEST EXCEEDS MAXIMUM.

1298573444 WORDS REQUIRED 300000000 AVAILABLE.

Thus, it seems that there are not enough memory to carry this job. However, in my input file I have set

$MCSCF IFORB=.T. $END

$XMCQDPT IFORB(1)=-1,1,1 $END

as described in:

http://classic.chem.msu.su/cgi-bin/ceilidh.exe/gran/gamess/forum/?C35e9ea902bHW-8295-1009+00.htm

these settings will avoid the first integral transformation and CASCI procedure (performed by the routine MQCACI) by overlapping part of calculations with those performed at the MCSCF stage and reusing them at XMCQDPT2 stage.

So, why this error occurred and is there a way to resolve this problem? Thanks.

The system I studied is the same as ref:

http://link.springer.com/article/10.1134%2FS1990793108050023?LI=true

The NACT and NELS I used is also same to the above ref, so this job should be carried out by firefly.

The part of my input file:

$CONTRL SCFTYP=MCSCF RUNTYP=ENERGY EXETYP=RUN MAXIT=100 ICHARG=-1

MULT=1 FSTINT=.T. GENCON=.T. ITOL=30 ICUT=11 INTTYP=HONDO

NOSYM=1 WIDE=.T. MPLEVL=2 $END

$SYSTEM MWORDS=300 KDIAG=0 NOJAC=100 TIMLIM=60000.0 $END

$SYSTEM MKLNP=1 NP=12 $END

$P2P P2P=.T. DLB=.T. $END

$SMP SMPPAR=.T. $END

$SCF DIRSCF=.T. FDIFF=.F. NCONV=8 $END

$TRANS MPTRAN=2 DIRTRF=.T. AOINTS=DIST ALTPAR=.T. MODE=112 $END

$MCSCF CISTEP=ALDET FULLNR=.F. SOSCF=.T. MAXIT=150 $END

$MCSCF IFORB=.T. $END

$DET NCORE=49 NACT=14 NELS=16 NSTATE=6 WSTATE(1)=1,1 $END

$XMCQDPT NSTATE=2 EDSHFT=0.02 THRGEN=1D-12 $END

$XMCQDPT IFORB(1)=-1,1,1 WSTATE(1)=1,1,-0 AVECOE(1)=1,1,-0 $END

$BASIS GBASIS=N31 NGAUSS=6 NDFUNC=1 NPFUNC=1 DIFFSP=.TRUE. $END

$GUESS GUESS=MOREAD NORB=359 $END

$MCQFIT $END

Sun Jan 6 '13 10:41am

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