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# Multi-node execution (4 nodes × 64 cores = 256 core parallel)
$ osub -np 64 --nodes 4 input.inp
# Allocate more resources to increase memory per core (8 cores in parallel, 2400 MB/core)
$ osub -np 16 -mp 8 -m 2400 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
# Do not use the compute node's local scratch (intermediate calculation results can be seen in the working directory)
$ osub -N 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 to allocate | 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 |
Input File Processing
Automatic Handling of External File References
osub automatically detects external file references in input files and converts relative paths to absolute paths to ensure proper execution in scratch directories.
Files Automatically Detected as External
Strings containing periods (excluding decimal numbers)
Processing Behavior
- Relative paths → Automatically converted to absolute paths (reflected in
<original_filename>.ap) - Absolute paths → Left unchanged
- Non-existent files → A warning is displayed during job submission
Explicit Specification of External Files
To manually specify files that are not automatically detected:
# Explicitly specify files without periods
# (The entries 'basis' and 'coord' in the input file will be converted to absolute paths)$ osub --external-files basis --external-files coord input.inp
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
# Allocate more resources to increase memory per core
$ osub -np 16 -mp 8 -m 2400 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.