WIEN2k¶

WIEN2k performs electronic structure calculations of solids using density functional theory (DFT). It is based on the full-potential (linearized) augmented plane-wave ((L)APW) + local orbitals (lo) method, one of the most accurate schemes for band structure calculations.

Wien2k is available on Cori. It is important for users to follow the instructions posted here to use Wien2k on NERSC systems.

How to access WIEN2k¶

NERSC uses modules to manage access to software. To use the default version of WIEN2k, include the following line:

cori$ module load wien2k

in your ~/.bashrc or ~/.cshrc files. To see all the available modules, do

cori$ module avail wien2k

How to run WIEN2K¶

To run Wien2k jobs on Cori, you need to do the following:

prepare the WIEN2K environment¶

Loading the wien2k module in your shell startup file, ~/.bashrc or ~/.cshrc file for Cori, depending on your default shell (~/.cshrc for csh, ~/.bashrc for bash).

cori$ module load wien2k

If you run Wien2k jobs on a single node only, then you do not have to have to load the wien2k module in the shell startup files.

use a job script¶

Using a job script similar to the sample job scripts below to submit batch jobs,

#!/bin/bash
#SBATCH -n 64 
#SBATCH -t 03:00:00
#SBATCH -q regular
#SBATCH -J test_wien2k 
#SBATCH -C haswell

#module load wien2k
#generating .machines file for k-point and mpi parallel lapw1/2
let ntasks_per_kgroup=1
gen.machines -m $ntasks_per_kgroup

#need to disable SLURM envs hereafter
unset `env|grep SLURM_|awk -F= '{print $1}'`

#put your Wien2k command here
run_lapw -p -i 2 -ec .0001 -I -in1ef

#remove leftover .machines file
rm -fr .machine* 

#!/bin/bash
#SBATCH -N 4
#SBATCH -n 128
#SBATCH -t 03:00:00
#SBATCH -q regular
#SBATCH -C haswell
#SBATCH -J test_wien2k 

#module load wien2k
#generating .machines file for k-point and mpi parallel lapw1/2
let ntasks_per_kgroup=8
gen.machines -m $ntasks_per_kgroup

#need to disable SLURM envs hereafter
unset `env|grep SLURM_|awk -F= '{print $1}'`

#put your Wien2k command here
run_lapw -p -i 2 -ec .0001 -I -in1ef 

#remove leftover .machines file
rm -fr .machine*

Using w2web¶

Wien2k on Cori was built with the graphical user interface w2web enabled. To use w2web, you must use a local ssh tunnel for security concern. You should not point a web browser to directly to Cori (Wien2k manual may instruct you to do so), instead you should use a secure local tunnel to forward a given port to it, but it does allow a given local port to be forwarded through a secure local tunnel.

You can use ssh as follows:

ssh -L 4650:localhost:4660 cori.nersc.gov  

After you login, you should load the wien2k module, and then run the w2web application. It will ask you to pick a port number: in this example the port number is 4660. After pointing your web browser to http://localhost:4650, you should be able to see w2web's startup screen.

If you use windows and the F_secure or putty shell client to access Cori, then specify a local tunnel as follows.

Open the F-Secure shell client, and choose Edit→settings. This will pop up a settings window, in which you should click add. Another pop-up window will then appear, requesting that you define your local tunnel. Enter

• 4650 in the source port field
• 4660 in the destination field
• cori.nersc.gov in the destination host field

Using local tunnels with putty is similar, except that for the destination host field you enter cori.nersc.gov:4660 (there is no separate field for the destination port as with F-secure).

Documentation¶

WIEN2K was developed at the Institute for Materials Chemistry at the Technical University, Vienna. The Wien2k Textbooks website has a detailed description of the electronic structure methods available in Wien2k, and a set of technical notes. The Wien2k Users Manual is particularly useful.