QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: GJK on January 17, 2014, 13:18

Title: Speed and Number of Atoms-reg
Post by: GJK on January 17, 2014, 13:18

Dear Mr.Nordland,

We have 4 core processor and and 4GB RAM.(4 Nodes each)
Is that speed ok for running a device with more than 1000 atoms as you suggested in my previous post.If then what about the computational timing( for example Graphene nanoribbon (6,0) of 10 unit cells attached with a biosystem (say) having more than 1000 atoms.

Kindly clarify!

Title: Re: Speed and Number of Atoms-reg
Post by: Anders Blom on January 19, 2014, 23:53

It is very difficult to make exact predictions about calculations time etc. You can however set up the system you are interested in and then estimate the memory usage (http://quantumwise.com/documents/tutorials/latest/MemoryUsage).

4 GB/node sounds a bit low for so many atoms, but you didn't specify if you intend to use DFT or some of the semi-empirical models - this makes a large difference..

Title: Re: Speed and Number of Atoms-reg
Post by: GJK on January 23, 2014, 13:25

Thank you

I am using DFT.

Title: Re: Speed and Number of Atoms-reg
Post by: Anders Blom on January 24, 2014, 12:45

1000 atoms DFT will take some time.