I've never seen an error like this before - can you post part of your output file right before the error appears? Have you contacted Gaussian support? They tend to recognize unusual errors better than the average user might.

Thank you Allen for your help. These "dumping /fiocom/" statement occur before the final error "Attempt to create subfile not contained in parent".

Number 2992 2993 2994 2995 2996 2997

Base 22787008 22779575 22778062 22376809 21975556 21885600

End 22841251 22787008 22779575 22778062 22376809 21975484

End1 22841251 22787008 22779575 22778062 22376809 21975484

Wr Pntr 22841251 22787008 22779575 22778062 22376809 21975484

Rd Pntr 22841251 22787008 22779575 22778062 22376809 21975484

Length 54243 7433 1513 401253 401253 89884

Int.Num 187 188 189 190 191 192

Number 2998 2999 9995 9996 9997 9998

Base 21484347 21395383 36272024 77485927 77082374 74123511

End 21885600 21484347 36418713 77889480 77485927 77082374

End1 21885600 21484347 36418713 77889480 77485927 77082374

Wr Pntr 21885600 21484347 36272024 77493560 77082374 77066274

Rd Pntr 21885600 21484347 36272024 77491256 77481695 77066274

Length 401253 88964 146689 403553 403553 2958863

Int.Num 193 194 195 196 197 198

Number 9999

Base 71164648

End 74123511

End1 74123511

Wr Pntr 71219491

Rd Pntr 71219491

Length 2958863

Int.Num 199

dumping /fiocom/, unit = 2 NFiles = 8 SizExt = 32768 WInBlk = 512

defal = F LstWrd = 86528 FType=2 FMxFil=10000

Number 0 508 522 536 538 634

Base 84877 40448 40678 63556 68912 40884

End 86528 40478 40884 68912 74268 63556

End1 86528 40478 40884 68912 74268 63556

Wr Pntr 84877 40448 40678 63556 68912 40884

Rd Pntr 84877 40448 40678 63556 68912 40884

Length 1651 30 206 5356 5356 22672

Int.Num 1 2 3 4 5 6

Number 685 998

Base 74268 40478

End 84877 40678

End1 84877 40678

Wr Pntr 74268 40478

Rd Pntr 74268 40478

Length 10609 200

Int.Num 7 8

dumping /fiocom/, unit = 3 NFiles = 1 SizExt = 524288 WInBlk = 512

defal = F LstWrd = 67072 FType=2 FMxFil=10000

Number 0

Base 40448

End 67072

End1 67072

Wr Pntr 40448

Rd Pntr 40448

Length 26624

Int.Num 1

Attempt to create subfile not contained in parent.

FileIO: IOper=28 IFilNo(1)=-19997 Len= 146689 IPos= 258064 Q= 5382818328

Error termination in NtrErr:

NtrErr Called from FileIO.

FileIO usually means problems with too large files, but I haven't seen this exact problem yet. You're also using CCSD with large basis set which has huge requirements for memory/disk space, so that also points to a likely problem with too large files being created over the course of calculations.

Following