CCSD(T) computation

Just Got Here

12:29:30 PM PDT - Fri, Apr 6th 2012
I am a new NWCHEM user. I want to compute the CCSD(T) energy of a system composed up to 20 atoms, employing the Dunning series of basis set. I made some efforts, however all of them failed due to the production of large files. Is there anyone who could help me, offering some hints, in order to overcome this issue. Thanks in advance. Aggelos Avramopoulos

Forum Vet

1:29:15 PM PDT - Mon, Apr 9th 2012
Are you running the CCSD(T) code or the TCE code? In the former you can reduce disk usage by setting "nodisk" in the ccsd input block. Are you correlating all electrons or freezing the core electrons (i.e. how many electrons are you correlating with how many basis functions)? Freezing the core-electrons can dramatically reduce disk and compute needs. What are your memory settings? How many processors are you using? Could you post the input and key part of the output? Thanks, Bert Quote:Aggavramopoulos Apr 6th 7:29 pm I am a new NWCHEM user. I want to compute the CCSD(T) energy of a system composed up to 20 atoms, employing the Dunning series of basis set. I made some efforts, however all of them failed due to the production of large files. Is there anyone who could help me, offering some hints, in order to overcome this issue. Thanks in advance. Aggelos Avramopoulos