https://wiki.fysik.dtu.dk/gpaw/

GPAW is a Density Functional Theory real-space grid based projector-augmented wave calculator.

It is working best coupled together with the Atomic Simulation Environment(ASE) that works as an interface to the GPAW calculator. ASE is described on this wiki.

GPAW can be found and is documented at the webpage http://wiki.fysik.dtu.dk/gpaw

The remaining of this page contains:

• Example script
• Running GPAW on Glenn
• Running GPAW on Hebbe

Example script

Here is an example script showing how to get the potential energy of a infinite fcc palladium crystal using the real space grid(finite difference stencil):

	from ase.lattice import bulk
	from gpaw import GPAW

	#Parameters:
	k0 = 10 #BZ sampling 
	a0=3.996 #PBE self-consistent Pd lattice parameter [Ang].
	h0 = 0.18 #Real space grid density[Ang]

	crystal = bulk(name="Pd",crystalstructure="fcc",a=3.996) #Set up the crystal with ASE

	calc = GPAW(mode="fd",kpts = (k0,k0,k0),h=h0, txt='bulkPd.txt') #Initialize caclulator
	crystal.set_calculator(calc) #Connect the calculator to the atoms.

	energy = crystal.get_potential_energy() #start the energy calculation

	print "Found potential energy of crystal: ", energy #print the result to sys.stdout

Running GPAW on Glenn

You should load the following modules on Glenn:

	module load python/py27/2.7.2
	module load gcc/4.9/4.9.2
	module load acml/gfortran64_fma4_mp/5.3.0
	module load numpy/py27/1.8.1-gcc48-acml_mp
	module load scipy/py27/0.10.1-gcc47-acml
	module load ase/3.9.1 
	module load intel-mpi/5.0.1.035 
	module load gpaw/0.11.0.13004

e.g. by adding the these lines to your .bashrc file or load them in your submit file (see example below).

Submitting a script called for example “example.py", involves using MPI and a call to gpaw-python as follows:

	#!/usr/bin/env bash
	#SBATCH -p glenn
	#SBATCH -A SNIC2014-11-18
	#SBATCH -o out.txt
	#SBATCH -e err.txt
	#SBATCH -J pdbulk
	#SBATCH -N 1
	#SBATCH -t 01:00:00

	module purge

	module load python/py27/2.7.2
	module load gcc/4.9/4.9.2
	module load acml/gfortran64_fma4_mp/5.3.0
	module load numpy/py27/1.8.1-gcc48-acml_mp
	module load scipy/py27/0.10.1-gcc47-acml
	module load ase/3.9.1 
	module load intel-mpi/5.0.1.035 
	module load gpaw/0.11.0.13004

	mpirun gpaw-python example.py

Running GPAW on Hebbe

On Hebbe the following module should be loaded

	module load GPAW