QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: Dipankar Saha on December 5, 2015, 15:42

Title: Size of the Dense Matrices
Post by: Dipankar Saha on December 5, 2015, 15:42

Hi,
How can I estimate the reqd. memory ....when the  size of the Dense Matrices are shown as, 4320 x 4320 (285 MB per matrix)....in the Log file....

Regards_
Dipankar

Title: Re: Size of the Dense Matrices
Post by: Dipankar Saha on December 6, 2015, 07:35

Apart from that_
sometimes we find a line saying :
"Phonon :  Calculating forces for displacement 12  / 108 " ....... /

How this no.  e.g. "108" is calculated ?
I wanted to mean_what does it depend on...?!! 

Title: Re: Size of the Dense Matrices
Post by: Jess Wellendorff on December 6, 2015, 15:07

I suggest you use the MemoryUsage tool for obtaining memory estimates:

bulk_configuration.setCalculator(calculator)
from NanoLanguage import *
MemoryUsage(bulk_configuration)


The number of displacements needed to compute the dynamical matrix is 6*number of atoms.

Title: Re: Size of the Dense Matrices
Post by: Dipankar Saha on December 7, 2015, 14:01

Quote from: Jess Wellendorff on December  6, 2015, 15:07

The number of displacements needed to compute the dynamical matrix is 6*number of atoms.

6* no. of atoms??!! :o /  I will send you the script rather.....!!

Thanks & Regards_
Dipankar

Title: Re: Size of the Dense Matrices
Post by: Umberto Martinez on December 14, 2015, 13:35

There are several tutorials that describe the dynamical matrix and how the number of displacements is defined.
http://quantumwise.com/publications/tutorials/itemlist/category/94-phonons-and-thermal-properties