Submit ORCA jobs (osub)
Overview
osub is a command-line tool that simplifies job submission for the quantum chemistry software ORCA.
You can submit a job by simply providing an input file.
Supported ORCA Versions
4.2.1, 5.0.3, 5.0.4, 6.0.1, 6.1.0 (default)
Basic Usage
Simplest Execution Example
$ osub input.inp
This runs the calculation with the following default settings:
- ORCA 6.1.0
- 8 CPU cores
- 1200 MB/core memory
- 72-hour time limit
Commonly Used Option Examples
# Specify CPU count and memory
$ osub -np 16 -m 1500 input.inp# Specify ORCA version
$ osub -v 5.0.4 -np 4 input.inp# Large memory (largemem)
$ osub -np 64 -m 6000 -j largemem input.inp# Multi-node execution (4 nodes × 64 cores = 256 core parallel)
$ osub -np 64 --nodes 4 input.inp# Submit multiple files at once (sequential execution)
$ osub -np 8 *.inp
Main Options
Resource Specification
| Option | Description | Default |
|---|---|---|
-np, --ncpus | Number of CPUs | 8 |
-m, --maxcore | Memory per core (MB) | 1200 |
--nodes | Number of nodes | 1 |
-mp, --mpiprocs | MPI processes/node | Same as ncpus |
-t, --walltime | Walltime (hh:mm:ss) | 72:00:00 |
ORCA Configuration
| Option | Description | Default |
|---|---|---|
-v, --version | ORCA version | 6.1.0 |
--noedit | Skip input file editing | False |
-ng, --nprocs-group | Subtask parallelism (ORCA6 only) | - |
Job Control
| Option | Description | Default |
|---|---|---|
-j, --jobtype | Specify job type | Auto-detect |
-g, --group | User group specification | Primary group |
-P, --prep-only | Generate script only | False |
Other Options
| Option | Description | Default |
|---|---|---|
-O, --overwrite | Overwrite existing files | False |
--mail | Email notification | False |
--name | Specify job name | - |
--autoname | Auto-generate job name from filename | False |
Troubleshooting
Common Errors and Solutions
1. ERROR: invalid ncpus value
# Cause: 65–127 cores are not available on the system
❌ $ osub -np 100 input.inp
✅ $ osub -np 64 input.inp
✅ $ osub -np 128 input.inp
2. Memory Shortage
# Increase memory and re-run
$ osub -np 8 -m 1500 input.inp
# Or use large memory job type
$ osub -np 64 -j largemem input.inp
Display Debug Information
# Generate the job script without submitting it
$ osub -P -np 8 input.inp
Generated Files
Job Script
H-<PID>.sh: PBS job script
Edited Input File
<original_filename>.ap: Modified input file with resource settings appended
Output Files
<input_filename>.out: ORCA calculation log
Support & Contact
For questions or bug reports, please contact your system administrator.