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["M.T.Storr" <m.t.storr@reading.ac.uk>]

HI,

I have a quick question concerning Abinit memory requirements. I have 
tried running an identical calculation on two different machines as 
outlined below, however upon running the calculations the calculated 
memory requirements are totally different. As can be seen the echoed 
parameters are identical in both cases except for the mkmem variable yet 
on one system the required memory is said to be 374 Mb, while on the other it 
is said to be 4244 Mb. My question is therefore where does the mkmem 
variable come from and why is there such a vast difference in the required 
memory for the same calculation.

On an IBM SP3 machine with running on 28 processors -

 DATASET    1 : space group P-1 (#  2); Bravais aP (primitive triclinic)
============================================================================
 Values of the parameters that define the memory need for DATASET  1.
   intxc =         0  ionmov =         3    iscf =         5     ixc =
1
  lmnmax =         3   lnmax =         3   mband =        34  mffmem =
1
   mgfft =        60   mkmem =        31 mpssoang=         4     mpw =
9200
  mqgrid =      1201   natom =         3    nfft =    216000    nkpt =
432
  nloalg =         4  nspden =         2 nspinor =         1  nsppol =
2
    nsym =         2  n1xccc =      2501   ntype =         2  occopt =
1
============================================================================
 This job should need less than                     374.572 Mbytes of
memory.
 Rough estimation (10% accuracy) of disk space for files :
 WF disk file :     27.830 Mbytes ; DEN or POT disk file :      3.298
Mbytes.
============================================================================

While on a Linux cluster with 8 processors-

 DATASET    1 : space group P-1 (#  2); Bravais aP (primitive triclinic)
============================================================================
 Values of the parameters that define the memory need for DATASET  1.
   intxc =         0  ionmov =         3    iscf =         5     ixc =
1
  lmnmax =         3   lnmax =         3   mband =        34  mffmem =
1
   mgfft =        60   mkmem =       432 mpssoang=         4     mpw =
9200
  mqgrid =      1201   natom =         3    nfft =    216000    nkpt =
432
  nloalg =         4  nspden =         2 nspinor =         1  nsppol =
2
    nsym =         2  n1xccc =      2501   ntype =         2  occopt =
1
============================================================================
 This job should need less than                    4244.696 Mbytes of 
memory.
 Rough estimation (10% accuracy) of disk space for files :
 WF disk file :     27.830 Mbytes ; DEN or POT disk file :      3.298
Mbytes.
============================================================================