one more questions about an error in Gaussian

Hi,
     Sorry to bother again. There's one more questions about Gaussian.
 Recently, I've calculated the ground energy of a cation which contains about
 50 atoms by CISD. However, there was an error termination at the end. The
 Route Section and the error output are attached at the end of email.  I
 don't know the reason. Can anyone help me? Thanks a lot!
 # UCISD/6-31G(d) SCF=Tight Guess=Mix
 ------------------------------------------------------
 ----
 ----
 ----
  SCF Done:  E(UHF) =  -1662.87165162     A.U. after   39 cycles
              Convg  =    0.8574D-08             -V/T =  2.0012
              S**2   =   1.6627
  Annihilation of the first spin contaminant:
  S**2 before annihilation     1.6627,   after     1.8035
  Range of M.O.s used for correlation:    39   550
  NBasis=   550 NAE=   119 NBE=   118 NFC=    38 NFV=     0
  NROrb=    512 NOA=    81 NOB=    80 NVA=   431 NVB=   432
  Estimate disk for full transformation 76475988068 words.
  Semi-Direct transformation.
  ModeAB=           2 MOrb=           512 LenV=      45858810
  LASXX=   9165849841 LTotXX=  9165849841 LenRXX=  9165849841
  LTotAB= 17247043584 MaxLAS= 19899475200 LenRXY= 19899475200
  NonZer= 18331699682 LenScr= 27543408333 LnRSAI=           0
  LnScr1=           0 MaxDsk=          -1 Total=  56608733374
  SrtSym=           F ITran=            5
  JobTyp=1 Pass  1:  I=   1 to 512.
  LAS=         19899475200 but cannot sort more than 2147483647 items.
  Error termination via Lnk1e in /usr/local/g98/l804.exe.
  Job cpu time:  0 days  8 hours 47 minutes 25.8 seconds.
  File lengths (MBytes):  RWF=***** Int=    0 D2E=    0 Chk=    5 Scr=*****
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 Regards,
 Kiniu WONG Kin-Yiu
 Undergraduate student
 Department of Physics
 The Chinese University of Hong Kong
 Email: kiniu (+ at +) cuhk.edu.hk  or  kyiwong (+ at +) phy.cuhk.edu.hk