ORCA

ORCA is an ab initio quantum chemistry program package that contains modern electronic structure methods including density functional theory, many-body perturbation, coupled cluster, multireference methods, and semi-empirical quantum chemistry methods. Its main field of application is larger molecules, transition metal complexes, and their spectroscopic properties. ORCA is developed in the research group of Frank Neese. Visit ORCA Forum for additional information.

 

Availability and Restrictions

Versions

ORCA is available on the OSC clusters. These are the versions currently available:

VERSION ruby owens pitzer notes
4.0.1.2   X X OpenMPI 2.0.2
4.1.0   X X OpenMPI 3.1.3
4.1.1   X X OpenMPI 3.1.3
4.1.2   X* X* OpenMPI 3.1.3
* Current default version

You can use module spider orca to view available modules for a given machine. Feel free to contact OSC Help if you need other versions for your work.

Access

ORCA is available to OSC academic users; users need to sign up ORCA Forum. You will receive a registration confirmation email from the ORCA management. Please contact OSC Help with the confirmation email for access.

Publisher/Vendor/Repository and License Type

ORCA, Academic (Computer Center)

Usage

Usage on Owens

Set-up

ORCA usage is controlled via modules. Load one of the ORCA modulefiles at the command line, in your shell initialization script, or in your batch scripts. To load the default version of ORCA module, use module load orca. To select a particular software version, use module load orca/version. For example, use module load orca/4.1.0to load ORCA version 4.1.0 on Owens. 

IMPORTANT NOTE: You need to load correct compiler and MPI modules before you use ORCA. In order to find out what modules you need, use module spider orca/{version}.

Batch Usage

When you log into owens.osc.edu you are actually logged into a linux box referred to as the login node. To gain access to the mutiple processors in the computing environment, you must submit your job to the batch system for execution. Batch jobs can request mutiple nodes/cores and compute time up to the limits of the OSC systems. Refer to Queues and Reservations and Batch Limit Rules for more info.  Batch jobs run on the compute nodes of the system and not on the login node. It is desirable for big problems since more resources can be used.

Interactive Batch Session

For an interactive batch session one can run the following command:

qsub -I -l nodes=1:ppn=1 -l walltime=00:20:00

which requests one core (-l nodes=1:ppn=1), for a walltime of 20 minutes (-l walltime=00:20:00). You may adjust the numbers per your need.

Non-interactive Batch Job

batch script can be created and submitted for a serial or parallel run. You can create the batch script using any text editor you like in a working directory on the system of your choice. Below is the example batch script for a parallel run:

#PBS -N orca_mpi_test
#PBS -l walltime=0:10:0
#PBS -l nodes=2:ppn=28
cd $PBS_O_WORKDIR
module load openmpi/3.1.0-hpcx
module load orca/4.1.0
module list

pbsdcp -p h2o_b3lyp_mpi.inp $TMPDIR
cd $TMPDIR
$ORCA/orca h2o_b3lyp_mpi.inp "--machinefile $PBS_NODEFILE" > h2o_b3lyp_mpi.out
pbsdcp -g h2o_b3lyp_mpi.out $PBS_O_WORKDIR 

 

Usage on Pitzer

Set-up

ORCA usage is controlled via modules. Load one of the ORCA modulefiles at the command line, in your shell initialization script, or in your batch scripts. To load the default version of ORCA module, use module load orca. To select a particular software version, use module load orca/version. For example, use module load orca/4.1.0to load ORCA version 4.1.0 on Pitzer. 

IMPORTANT NOTE: You need to load correct compiler and MPI modules before you use ORCA. In order to find out what modules you need, use module spider orca/{version}.

Batch Usage

When you log into pitzer.osc.edu you are actually logged into a linux box referred to as the login node. To gain access to the mutiple processors in the computing environment, you must submit your job to the batch system for execution. Batch jobs can request mutiple nodes/cores and compute time up to the limits of the OSC systems. Refer to Queues and Reservations and Batch Limit Rules for more info.  Batch jobs run on the compute nodes of the system and not on the login node. It is desirable for big problems since more resources can be used.

Interactive Batch Session

For an interactive batch session one can run the following command:

qsub -I -l nodes=1:ppn=1 -l walltime=00:20:00

which requests one core (-l nodes=1:ppn=1), for a walltime of 20 minutes (-l walltime=00:20:00). You may adjust the numbers per your need.

Non-interactive Batch Job

batch script can be created and submitted for a serial or parallel run. You can create the batch script using any text editor you like in a working directory on the system of your choice. Below is the example batch script for a parallel run:

#PBS -N orca_mpi_test
#PBS -l walltime=0:10:0
#PBS -l nodes=2:ppn=40
cd $PBS_O_WORKDIR
module load openmpi/3.1.0-hpcx
module load orca/4.1.0
module list

pbsdcp -p h2o_b3lyp_mpi.inp $TMPDIR
cd $TMPDIR
$ORCA/orca h2o_b3lyp_mpi.inp "--machinefile $PBS_NODEFILE" > h2o_b3lyp_mpi.out
pbsdcp -g h2o_b3lyp_mpi.out $PBS_O_WORKDIR 

Know Issues

Update: 04/17/2019 
Version: 4.1.0

For a MPI job that request multiple nodes, the job can be run from a globally accessible working directory, e.g., home or scratch directories. It is useful if one needs more space for temporary files. However, ORCA 4.1.0 CANNOT run a job on our scratch filesystem. The issue has been reported on ORCA forum.  This issue has been resolved in ORCA 4.1.2.

Further Reading

User manual is available from the ORCA Forum 

Supercomputer: 
Service: