ORCA

Overview

ORCA is an ab initio, DFT and semiempirical SCF-MO package for quantum chemistry with specific emphasis on spectroscopic properties of open-shell molecules.

Versions 5.0.3, 5.0.2, 4.2.1, 4.1.2, 4.1.1 and 4.0.1.2 are available.

Version 5 – Installed Jan 2022 – Please note that there have been important changes to the license agreement that you must be aware of, and we have updated the information below to reflect this, please read it carefully.

Restrictions on use

These are the steps all user must do to be granted access to ORCA on the CSF. It will speed up your request if you do these steps before contacting us.

All users of the software must individually register and agree to the End User License Agreement (EULA), for which we also provide some guidance below. To do this you must

1. Register on the ORCA Forum.
2. You will then receive an email asking you to activate your account.
3. Once you have activated your account and have logged into the forum for the first time, you will be presented with the EULA.
4. You will need to read and agree (bottom of the page) to the EULA
5. Once you have agreed to the policy, you will be automatically sent an email confirming that you have agreed to the EULA. Forward this email to its-ri-team@manchester.ac.uk when you ask for access to ORCA.
6. Sending confirmation that you have registered only for the forum is not sufficient for us to grant you access to ORCA on the CSF.
7. Sending a copy of just the EULA is not sufficient.
8. EULA confirmation emails issued prior to July 2021 cannot be accepted as they cover older versions of the software.

FAQ: Which version of ORCA will I have access to?

By default from February 2022 all first time requests for ORCA will be given access to ORCA 5 only.

Older versions of ORCA may be removed from the CSF.

FAQ: I am already registered for ORCA 4 on the CSF, please can I have access to ORCA 5?

You cannot automatically be added to the ORCA 5 software group. You must read the EULA and the guidance below. If you agree in an email to its-ri-team@manchester.ac.uk to abide by the Terms and Conditions of the EULA we will enable access to version 5.

If you have never registered for ORCA use then emailing us with an agreement to the EULA is not sufficient, you must follow the steps above.

FAQ: I am a visitor/collaborator who needs access to the software or DATA generated by it. Am I allowed access?

Only visitors and collaborators from other academic institutions may use the software and any DATA generated with ORCA. Such visitors and collaborators must also register separately and enter into their own EULA for ORCA before using the software. Such visitors and collaborators are subject to the terms of the EULA as set out below.

Some guidance, which is not intended as a replacement for the EULA, is given below.

EULA Guidance

This is not intended as a replacement for the EULA.

Important change to the ORCA agreement July 2020

The ORCA 5 license introcduced a new clause regarding DATA which is classed as “all data generated” by ORCA. This includes, but is not limited to any software or algorithms that you generate which is (fully or partially) based on data obtained from ORCA. This DATA, and your use of it including in other software, is subject to the ORCA EULA.

Thus the rights and restrictions of the ORCA license apply to the software AND any DATA generated from it, this includes any sharing of the DATA.

What may ORCA be used for?

The EULA stipulates that:

• the software may only be for academic purposes, including teaching and research
• publication in a scientific is permitted
• copyright notices, a notice referring explicitly to the EULA and the disclaimer of warranties (as per Clause 3d) must remain in the software and its DATA

What may ORCA not be used for?

You MUST NOT use ORCA:

• for research and development for commercial purposes
• for research and development in cooperation or other collaboration with or sponsored by a for-profit organization
• for research and development for a for-profit organization
• for any work that is directly funded by or in collaboration with a military department, e.g. Ministry of Defence in the UK or an equivalent abroad.

It is not permitted:

• to use ORCA on the CSF for “Private Use” (as defined in clause 1d of the EULA)
• to share DATA generated with ORCA with third parties for purposes other than academic purposes.
• to modify, translate, reverse engineer, decompile or disassemble ORCA or duplicate, transfer, modify it or derive works from it outside the scope of the EULA

How should the program be cited?

The use of ORCA should be cited as per clause 5 of the EULA.

Note that any patent that is filed for as a result of using ORCA must be notified to the Max Planck Institute.

Set up procedure

We now recommend loading modulefiles within your jobscript so that you have a full record of how the job was run. See the example jobscript below for how to do this. Alternatively, you may load modulefiles on the login node and let the job inherit these settings

Load only one of the following:

module load apps/binapps/orca/5.0.3
module load apps/binapps/orca/5.0.2
module load apps/binapps/orca/4.2.1
module load apps/binapps/orca/4.1.2
module load apps/binapps/orca/4.1.1
module load apps/binapps/orca/4.0.1.2

Note: this loads an mpi module required to run ORCA in parallel, therefore unloading the ORCA module will also unload this mpi module.

Running the application

ORCA must be run in batch only. The examples below use version 5.0.2, if you wish to use 4.0.1.2, 4.1.1, 4.1.2, or 4.2.1 then load one of the other modulefiles.

Serial batch job submission

• Make sure you have the module loaded.
• Create or upload an input file to your working directory. In the example below we have called this file my.orca.inp.
• Write a submission script, for example:

  #!/bin/bash --login
  ## Use the current directory as the working directory - input and output files are here
  #$ -cwd
  
  module load apps/binapps/orca/5.0.3
  
  $ORCA_HOME/orca my.orca.inp > out.txt
  

• Submit with: qsub scriptname

Parallel batch job submission

• Make sure you have the module loaded.
• Create or upload an input file to your working directory. In the example below we have called this file my.orca.inp.
• Write a submission script, for example:

  #!/bin/bash --login
  #$ -cwd
  #$ -pe smp.pe 4          # Number of cores (2--32). Must match the number in your ORCA input file!
  
  module load apps/binapps/orca/5.0.3
  
  $ORCA_HOME/orca my.orca.inp > results.${JOB_ID}.txt
  

• Your input file needs one of the following lines at the top of it (including the !) to tell it how many cores to use:

  ! PAL4
       #
       # Must match the number of cores requested in your jobscript!
       # Maximum permitted using this command is 8 cores (PAL8).
       # See the alternative format below to request more than 8 cores.
  
  

  or, using the alternative command, which allows up to 32 cores:

  %pal nprocs 4
              #
              # Must match the number of cores requested in your jobscript!
              # Maximum permitted using this command is 32 cores.
  

• The number you specify after PAL or %pal nprocs must match that on the #$ -pe line in your submission script to avoid scheduling issues.
• The maximum number of cores that ORCA can use if using the ! PALn keyword is 8 because only ! PAL2 to ! PAL8 keywords are supported.
• The maximum number of cores that ORCA can use if using the %pal nprocs is 32
• Typically ORCA scales well on up to 8 CPUs. For example, coupled cluster calculations usually scale well up to at least 8 processors but probably it is also worthwhile to try 16. Please do the scaling test on your applications and accordingly set the CPUs number.
• smp.pe must be used pe for parallel ORCA jobs.
• The input file must be suffixed .inp
• To submit the job: qsub scriptname
• Note: MRCI has not been parallelized so must be run as a serial job.

Further info

A detailed user manual is available on the official ORCA website.