how to convert memory in bytes or words to memory in MA or GA ?


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Dear Nwchem developers and users,

I need to run ccsd(t) calculations on large systems. But everytime I try I get an error message displaying the requested memory needed, but in GA or MA unity. Let's consider this case where I ask 1950mw, that is 15.6 GB of memory :



memory 1950 mw
...
         Memory information
------------------

heap = 511180801 doubles = 3900.0 Mbytes
stack = 511180801 doubles = 3900.0 Mbytes
global = 1022361600 doubles = 7800.0 Mbytes (distinct from heap & stack)
total = 2044723202 doubles = 15600.0 Mbytes
verify = yes
hardfail = no
...
...
The CCSD calculation needs at least          36980521600 of global GA memory per processor !                                 
The CCSD calculation needs at least 91875376 of local MA memory !



The problem is that I don't understand this GA or MA unity. I searched the documentation and read the section :
http://nwchemgit.github.io/index.php/Release62:Top-level#MEMORY

but, I still don't understand how to convert a memory in bytes or words, to GA or MA to fulfill my ccsd(t) calculation requirement. Could you please advise me ?

Thanks & Regards,
Edrisse