[gpaw-users] scaling in PW codes

[naromero at alcf.anl.gov]

Hi,

This question is not specific to GPAW. I have brought this up on the list
before.

What is the scaling of computation for V_ext*Psi in PW codes w.r.t to N_b, N_p,
and N_g (number of bands, number of projectors, and number of planewave
coefficients, respectively)?

One paper, I read. See the PDF in my drop box:
https://spideroak.com/browse/share/naromero_work/abinitio123

claims:
V_ext*Psi = N_p*N_g + N_g*log(N_g) + N_b*N_g + N_p*N_b*N_g

I believe the third and fourth term come from the non-local and local
components of the pseudopotential:
V_nl*Psi ~ N_p*N_p*N_g
V_local*Psi ~ N_b*N_g 

However I don't understand where the 1st and 2nd term come from? Does anyone know?

-- 
Nichols A. Romero, Ph.D.
Argonne Leadership Computing Facility
Argonne National Laboratory
Building 240 Room 2-127
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