Installation

Introduction

This guide will get you up and running in an environment for running high-throughput workflows with atomate2. atomate2 is built on the pymatgen, custodian, jobflow, and FireWorks libraries. Briefly:

  • pymatgen is used to create input files and analyze the output of materials science codes.

  • custodian runs your simulation code (e.g., VASP) and performs error checking/handling and checkpointing.

  • jobflow is used to design computational workflows.

  • FireWorks (optional) is used to manage and execute workflows on HPC machines.

Running and writing your own workflows are covered in later tutorials. For now, these topics will be covered in enough depth to get you set up and to help you know where to troubleshoot if you’re having problems.

Note that this installation tutorial is VASP-centric since almost all functionality currently in atomate2 pertains to VASP.

Objectives

  • Install and configure atomate2 on your computing cluster.

  • Validate the installation with a test workflow.

Installation checklist

Completing everything on this checklist should result in a fully functioning environment.

  1. Prerequisites

  2. Create a directory scaffold

  3. Create a conda environment

  4. Install Python packages

  5. Configure output database

  6. Configure pymatgen

  7. Run a test workflow

Prerequisites

Before you install, you need to make sure that your “worker” computer (where the simulations will be run, often a computing cluster) that will execute workflows can (i) run the base simulation packages (e.g., VASP, LAMMPS, FEFF, etc) and (ii) connect to a MongoDB database. For (i), make sure you have the appropriate licenses and compilation to run the simulation packages that are needed. For (ii), make sure your computing center doesn’t have firewalls that prevent database access. Typically, academic computing clusters as well as systems with a MOM-node style architecture (e.g., NERSC) are OK.

VASP

To get access to VASP on supercomputing resources typically requires that you’re added to a user group on the system you work on after your license is verified. Ensure that you have access to the VASP executable and that it is functional before starting this tutorial.

MongoDB

MongoDB is a NoSQL database that stores each database entry as a document, which is represented in JSON format (the formatting is similar to a dictionary in Python). Atomate2 uses MongoDB to:

  • Create a database of calculation results.

  • Store the workflows that you want to run as well as their state details (through FireWorks - optional).

MongoDB must be running and available to accept connections whenever you’re running workflows. Thus, it is strongly recommended that you have a server to run MongoDB or (simpler) use a hosting service. Your options are:

  1. Use a commercial service to host your MongoDB instance. These are typically the easiest to use and offer high-quality service but require payment for larger databases. MongoDB Atlas offers a free 500 MB server which is certainly enough to get started for small to medium-sized projects, and it is easy to upgrade or migrate your database if you exceed the free allocation.

  2. Contact your supercomputing center to see if they offer MongoDB hosting (e.g., NERSC has this, Google “request NERSC MongoDB database”).

  3. Self-host a MongoDB server.

If you’re just starting, we suggest option 1 (with a free plan) or 2 (if available to you). The third option will require you to open up network settings to accept outside connections properly which can sometimes be tricky.

Next, create a new database and set up an account with admin access. Keep a record of your credentials - we will configure jobflow to connect to them in a later step. Also, make sure you note down the hostname and port for the MongoDB instance.

Note

The computers that perform the calculations must have access to your MongoDB server. Some computing resources have firewalls blocking connections. Although this is not a problem for most computing centers that allow such connections (particularly from MOM-style nodes, e.g. at NERSC, SDSC, etc.), but some of the more security-sensitive centers (e.g., LLNL, PNNL, ARCHER) will run into issues. If you run into connection issues later in this tutorial, some options are:

  • Contact your computing center to review their security policy to allow connections from your MongoDB server (best resolution).

  • Host your Mongo database on a machine that you’re able to securely connect to, e.g. on the supercomputing network itself (ask a system administrator for help).

  • Use a proxy service to forward connections from the MongoDB –> login node –> compute node (you might try, for example, the mongo-proxy tool.

  • Set up an ssh tunnel to forward connections from allowed machines (the tunnel must be kept alive at all times you’re running workflows).

Create a directory scaffold for atomate2

Installing atomate2 includes the installation of codes, configuration files, and various binaries and libraries. Thus, it is useful to create a directory structure that organizes all these items.

  1. Log in to the compute cluster and create a directory in a spot on disk that has relatively fast access from compute nodes and that is only accessible by yourself or your collaborators. Your environment and configuration files will go here, including database credentials. We will call this place <<INSTALL_DIR>>. A good name might simply be atomate2.

  2. Now you should scaffold the rest of your <<INSTALL_DIR>> for the things we are going to do next. Run mkdir -p atomate2/{config,logs} to create directories named logs and config so your directory structure looks like:

atomate2
├── config
└── logs

Create a conda environment

Note

Make sure to create a Python 3.8+ environment as recent versions of atomate2 only support Python 3.8 and higher.

We highly recommend that you organize your installation of the atomate2 and the other Python codes using a conda virtual environment. Some of the main benefits are:

  • Different Python projects that have conflicting packages can coexist on the same machine.

  • Different versions of Python can exist on the same machine and be managed more easily (e.g. Python 2 and Python 3).

  • You have full rights and control over the environment. On computing resources, this solves permissions issues with installing and modifying packages.

The easiest way to get a Python virtual environment is to use the conda tool. Most clusters (e.g., NESRC) have Anaconda installed already which provides access to the conda binary. If the conda tool is not available, you can install it by following the installation instructions for Miniconda. To set up your conda environment:

  1. Create a new conda environment called atomate2 with Python 3.9 using conda create -n atomate2 python=3.9.

  2. Activate your environment by running conda activate atomate2. Now, when you use the command python, you’ll be using the version of python in the atomate2 conda environment folder.

  3. Consider adding conda activate atomate2 to your .bashrc or .bash_profile file so that it is run whenever you log in. Otherwise, note that you must call this command after every login before you can do work on your atomate project.

Install Python packages

Next, we will download and install all of the atomate2-related Python packages.

To install the packages run:

pip install atomate2

If you would like to use more specialized capabilities of atomate2 such as the phonon, Lobster or force field workflows, you would need to run one of

pip install atomate2[phonons]
pip install atomate2[lobster]
pip install atomate2[forcefields]

See pyproject.toml for all available optional dependency sets. More detailed instructions can be found under dev installation.

Configure calculation output database

The next step is to configure your MongoDB database that will be used to store calculation outputs.

Note

All of the paths here must be absolute paths. For example, the absolute path that refers to <<INSTALL_DIR>> might be /global/homes/u/username/atomate (don’t use the relative directory ~/atomate).

Warning

Passwords will be stored in plain text! These files should be stored in a place that is not accessible by unauthorized users. Also, you should make random passwords that are unique only to these databases.

Create the following files in <<INSTALL_DIR>>/config.

jobflow.yaml

The jobflow.yaml file contains the credentials of the MongoDB server that will store calculation outputs. The jobflow.yaml file requires you to enter the basic database information as well as what to call the main collection that results are kept in (e.g. outputs). Note that you should replace the whole <<PROPERTY>> definition with your own settings.

JOB_STORE:
  docs_store:
    type: MongoStore
    database: <<DB_NAME>>
    host: <<HOSTNAME>>
    port: <<PORT>>
    username: <<USERNAME>>
    password: <<PASSWORD>>
    collection_name: outputs
  additional_stores:
    data:
      type: GridFSStore
      database: <<DB_NAME>>
      host: <<HOSTNAME>>
      port: <<PORT>>
      username: <<USERNAME>>
      password: <<PASSWORD>>
      collection_name: outputs_blobs

Note

If you’re using a MongoDB hosted on Atlas (using the free plan linked above) the connection format is slightly different. Instead your jobflow.yaml file should contain the following.

JOB_STORE:
  docs_store:
    type: MongoURIStore
    uri: mongodb+srv://<<USERNAME>>:<<PASSWORD>>@<<HOST>>/<<DB_NAME>>?retryWrites=true&w=majority
    collection_name: outputs
  additional_stores:
    data:
      type: GridFSURIStore
      uri: mongodb+srv://<<USERNAME>>:<<PASSWORD>>@<<HOST>>/<<DB_NAME>>?retryWrites=true&w=majority
      collection_name: outputs_blobs

The URI key may be different based on the Atlas database you deployed. You can see the template for the URI string by clicking on “Databases” (under “Deployment” in the left hand menu) then “Connect” then “Connect your application”. Select Python as the driver and 3.12 as the version. The connection string should now be displayed in the box.

Note that the username and password are not your login account details for Atlas. Instead you must add a new database user by selecting “Database Access” (under “Security” in the left hand menu) and then “Add a new database user”.

Secondly, Atlas only allows connections from known IP addresses. You must therefore add the IP address of your cluster (and any other computers you’ll be connecting from) by clicking “Network Access” (under “Security” in the left hand menu) and then “Add IP address”.

Atomate2 uses two database collections, one for small documents (such as elastic tensors, structures, and energies) called the docs store and another for large documents such as band structures and density of states called the data store.

Due to inherent limitations in MongoDB (individual documents cannot be larger than 16 Mb), we use GridFS to store large data. GridFS sits on top of MongoDB and therefore doesn’t require any further configuration on your part. However, other storage types are available (such as Amazon S3). For more information please read advanced_storage.

atomate2.yaml

The atomate2.yaml file controls all atomate2 settings. You can see the full list of available settings in the Atomate2Settings docs. For now, we will just configure the commands used to run VASP.

Write the atomate2.yaml file with the following content,

VASP_CMD: <<VASP_CMD>>

This is the command that you would use to run VASP with parallelization (srun -n 16 vasp, ibrun -n 16 vasp, mpirun -n 16 vasp, …).

Finishing up

The directory structure of <<INSTALL_DIR>>/config should now look like

config
├── jobflow.yaml
└── atomate2.yaml

The last thing to configure atomate2 is to add the following lines to your .bashrc / .bash_profile file to set an environment variable telling atomate2 and jobflow where to find the config files.

export ATOMATE2_CONFIG_FILE="<<INSTALL_DIR>>/config/atomate2.yaml"
export JOBFLOW_CONFIG_FILE="<<INSTALL_DIR>>/config/jobflow.yaml"

where <<INSTALL_DIR>> is your installation directory.

Configure pymatgen

If you’re planning to run VASP, the last configuration step is to configure pymatgen to (required) find the pseudopotentials for VASP and (optional) set up your API key from the Materials Project.

Pseudopotentials

The pseudopotentials should be available on the compute machine. Follow the pseudopotential installation instructions in the pymatgen documentation and then return to this tutorial.

Materials Project API key

You can get an API key from the Materials Project by logging in and going to your [Dashboard](materials project). Add this also to your ~/.config/.pmgrc.yaml so that it looks like the following

PMG_VASP_PSP_DIR: <<INSTALL_DIR>>/pps
PMG_MAPI_KEY: <<YOUR_API_KEY>>

You can generate this file and set these values using the pymatgen CLI:

pmg config --add PMG_VASP_PSP_DIR /abs/path/to/psp PMG_MAPI_KEY your_api_key

Run a test workflow

To make sure that everything is set up correctly and in place, we’ll finally run a simple (but real) test workflow. We will first define a Python script to run the workflow. Next, we’ll submit a job to run the script. Finally, we’ll examine the database to check the job output. In this tutorial, we will be submitting an individual workflow manually. If you want to manage and execute many workflows simultaneously this can be achieved using the FireWorks package and is covered in Using atomate2 with FireWorks.

This particular workflow will only run a single calculation that optimizes a crystal structure (not very exciting). In the subsequent tutorials, we’ll run more complex workflows.

Define the workflow

Workflows are written using the jobflow software. Essentially, individual stages of a workflow are simple Python functions. Jobflow provides a way to connect jobs in a natural way. For more details on connecting jobs see: Chaining workflows.

Go to the directory where you would like your calculations to run (i.e., your scratch or work directory) and create a file called relax.py containing:

from atomate2.vasp.jobs.core import RelaxMaker
from jobflow import run_locally
from pymatgen.core import Structure

# construct an FCC silicon structure
si_structure = Structure(
    lattice=[[0, 2.73, 2.73], [2.73, 0, 2.73], [2.73, 2.73, 0]],
    species=["Si", "Si"],
    coords=[[0, 0, 0], [0.25, 0.25, 0.25]],
)

# make a relax job to optimise the structure
relax_job = RelaxMaker().make(si_structure)

# run the job
run_locally(relax_job, create_folders=True)

The run_locally function is a jobflow command that will execute the workflow on the current computing resource.

Submit the workflow

Next, make a job submission script called job.sh containing:

conda activate atomate2
python relax.py

The job submission script should include all the headers specific to your HPC resource. For example, if your machine uses the Grid Engine scheduler for submitting and running jobs, your script would look something like:

#!/bin/bash -l
#$ -N relax_si
#$ -P my_project
#$ -l h_rt=1:00:00
#$ -l mem=4G
#$ -pe mpi 16
#$ -cwd

# ensure you load the modules to run VASP, e.g., module load vasp

conda activate atomate2
python relax.py

Finally, submit the job to the queue using the normal scheduler command. For example on the Grid Engine scheduler, this would be using qsub job.sh.

Analyzing the results

Once the job is finished, you can connect to the output database and check the job output.

from jobflow import SETTINGS

store = SETTINGS.JOB_STORE

# connect to the job store
store.connect()

# query the job store
result = store.query_one(
    {"output.formula_pretty": "Si"}, properties=["output.output.energy_per_atom"]
)
print(result)

We query the database using the MongoDB query language. You can also connect to the database using graphical tools, such as Robo3T to explore your results.

The outputs of VASP calculations always have the same set of keys. This structure is called a schema. You can see the VASP calculation scheme in the TaskDocument section of the documentation.

Next steps

That’s it! You’ve completed the installation tutorial!

See the following pages for more information on the topics we covered here:

  • To see how to run and customize the existing Workflows in atomate2, try the Running Workflows tutorial (suggested next step).

  • To see how to manage and execute many workflows at once, try the Using atomate2 with FireWorks tutorial.

Troubleshooting and FAQ

My job failed

Check the job error files in the launch directory for any errors. Also, check the job standard output for a full log of the workflow execution and to check for a Python traceback.

I honestly tried everything I can to solve my problem. I still need help

There is a support forum for atomate2.