`submit`

Submitting a job

Using splash, you can easily submit an ORCA job to Nimbus using only an ORCA input file and a single terminal command.

To best demonstrate the use of splash, let’s look at the example of a geometry optimisation and frequency calculation for a benzene molecule.

benzene.inp

 !BP86 def2-svp OPT FREQ
 %PAL NPROCS 16 END
 %maxcore 2000
 *xyzfile 0 1 benzene.xyz

In this example the structure is located in a separate .xyz file - benzene.xyz, though splash does support input file coordinate specification.

benzene.xyz

 12
 Benzene
 H      1.2194     -0.1652      2.1600
 C      0.6825     -0.0924      1.2087
 C     -0.7075     -0.0352      1.1973
 H     -1.2644     -0.0630      2.1393
 C     -1.3898      0.0572     -0.0114
 H     -2.4836      0.1021     -0.0204
 C     -0.6824      0.0925     -1.2088
 H     -1.2194      0.1652     -2.1599
 C      0.7075      0.0352     -1.1973
 H      1.2641      0.0628     -2.1395
 C      1.3899     -0.0572      0.0114
 H      2.4836     -0.1022      0.0205

To submit a job for this calculation, simply run

splash submit benzene.inp

You should then see an message informing you that a submission script was created and subsequently submitted.

The job will be given the same name as your input file, and the output file for this calculation should appear in the current directory when the job starts running - for example

user@nimbus-1-login-1 ~/benzene $ ls
benzene.6718675.e  benzene.6718675.o  benzene.inp  benzene.out  benzene.slm  benzene.xyz

When the calculation has finished, been evicted, timed-out, or otherwise halted, you should see a new directory in the same location as your input and .xyz files. This directory will be named <jobname>_results and will contain all the files ORCA creates.

user@nimbus-1-login-1 ~/benzene $ ls
benzene.6718675.e  benzene.6718675.o  benzene.inp  benzene.out  benzene.slm  benzene.xyz  benzene_results

Submitting multiple jobs

You can submit more than one calculation at once by providing more than one input file to splash. For example

splash submit input_1.inp input_2.inp

You can even use a wildcard to submit jobs without typing each filename out

splash submit input_*.inp

Note that this will run all jobs in the current directory, and so can produce a large number of files in the same directory.

Providing coordinates within the input file

Instead of providing a separate .xyz file, it is possible to specify coordinates within the ORCA input file.

This feature is supported by splash and requires no additional effort on the part of the user.

Providing input orbitals

To provide ORCA with a set of orbitals, make sure you have both the MORead keyword and the %moinp "<gbw_filename>" line in your input file. Note that ORCA will not allow your specified file to have the same name-stem as the input file.

For the benzene example in the previous section, a correct input file would be

benzene.inp with input orbitals specified

 !BP86 def2-svp OPT FREQ MORead
 %moinp "new_orbs.gbw"
 %PAL NPROCS 16 END
 %maxcore 2000
 *xyzfile 0 1 benzene.xyz

The file <gbw_filename> must be in the same directory as the input file, and cannot contain any path information.

Selecting a compute instance

Specific Nimbus compute instances can be requested using the --instance option.

The full list of ORCA compatible instances currently known to splash are

spot-fsv2-2
spot-fsv2-4
spot-fsv2-8
spot-fsv2-16
spot-fsv2-32
spot-hc-44
spot-hbv2-120
paygo-fsv2-2
paygo-fsv2-4
paygo-fsv2-8
paygo-fsv2-16
paygo-fsv2-32
paygo-hc-44
paygo-hbv2-120

Note

You can only use instances to which you have been granted access. This is usually indicated by a QOS error at submission time. To resolve this, modify your access on the RCAM portal.

By default, splash submits to spot-fsv2-16 which has 16 cores and 2GB RAM per core, to change this default for your account add the following to your ~/.bash_rc file, where <instance> is one of those given above

export SPLASH_DEFAULT_INSTANCE=<instance>

Selecting a different version of ORCA

Several versions of ORCA are available on Nimbus - use module check <INSTANCE_NAME> ORCA to see the ORCA versions available for a given instance.

Note

You might get an error about termcolor when using module check. If you do, run pip install termcolor and then try again!

By default, splash will use the most recent version of ORCA (6.0.1), but a different version can be selected with the --orca_version <VALUE> optional argument.

Alternatively, to select a new default ORCA version and avoid having to enter this optional argument constantly, add the following to your ~/.bash_rc file, where <module_name> is one of those printed by module avail

export SPLASH_ORCA_MODULE=<module_name>

Warning

Beware: Not all Nimbus instances have access to the same ORCA versions.

More

Additional command line arguments for splash submit can be listed by running

splash submit -h

submit