Mod:Hunt Research Group/orca6 hpc

ORCA Installations Available on Raapoi

• To see a list of ORCA versions on Raapoi, run the following command

 module spider ORCA 

• You'll see the following versions listed.

Versions:
        ORCA/4.2.1
        ORCA/5.0.2
        ORCA/5.0.3
        ORCA/5.0.4
        ORCA/6.0.0-avx2
        ORCA/6.0.0
        ORCA/6.0.1
        ORCA/6.1.0-avx2-xtb

• To load any version, you have to check its requirements by the following command (I am trying for ORCA/6.1.0-avx2-xtb).

 module spider ORCA/6.1.0-avx2-xtb 

• It will tell you what modules you need to load before loading this specific version. See below:

ORCA: ORCA/6.1.0-avx2-xtb
-----------------------------------------------------------------------------------------------------------------------------------
    Description:
      ORCA is a flexible, efficient and easy-to-use general purpose tool for quantum chemistry with specific emphasis on
      spectroscopic properties of open-shell molecules. It features a wide variety of standard quantum chemical methods ranging
      from semiempirical methods to DFT to single- and multireference correlated ab initio methods. It can also treat
      environmental and relativistic effects.


    You will need to load all module(s) on any one of the lines below before the "ORCA/6.1.0-avx2-xtb" module is available to load.

      GCC/13.2.0  OpenMPI/4.1.6

• So in this case we have to load these modules as follows to use ORCA 6.1.0

module load GCC/13.2.0  
module load OpenMPI/4.1.6
module load ORCA/6.1.0-avx2-xtb

How to Submit an ORCA Job on Raapoi

• ORCA can be used on Raapoi with a Slurm submission script.
• ORCA 6.1.0 comes with xtb, so you don't need to load xtb separately.
• below is a sample script
• you will need to alter this to suit your needs
• There are comments in the script to facilitate replication.

#!/bin/bash
#Header for Slurm following
#SBATCH --job-name=CH3I_opt
#SBATCH --ntasks=8
#SBATCH --nodes=1
#SBATCH --time=05:00:00
#SBATCH --mem=16G
#SBATCH --partition=quicktest

#---- begin ORCA 6.1.0 specific part ----
# First we create a directory in Scratch with job ID where the job will run and store all temporary files
mkdir -p /nfs/scratch/hashmi/$SLURM_JOBID
cd /nfs/scratch/hashmi/$SLURM_JOBID

# Copy the files from your directory to scratch. Replace the path with your own path
cp /nfs/home/hashmimu/calculations/orca_calcs/molecule/*.* .

# Load ORCA and necessary modules
module load GCC/13.2.0
module load OpenMPI/4.1.6
module load ORCA/6.1.0-avx2-xtb
# Below are some necessary commands that make ORCA run smoothly
export OMPI_MCA_btl='^uct,ofi'
export OMPI_MCA_pml='ucx'
export OMPI_MCA_mtl='^ofi'

# Below command is the run the job. It is necessary to call ORCA with full path to run in parallel
/home/software/EasyBuild/software/ORCA/6.1.0-foss-2023b-avx2-xtb/bin/orca CH3I_opt.inp > CH3I_opt.out

# Calculate the files back from scratch to your directory
rm -f *.tmp*
cp -f molecule-td.* /nfs/home/hashmimu/calculations/orca_calcs/molecule
cp -f *.plt /nfs/home/hashmimu/calculations/orca_calcs/molecule  # Added this line for copying generated plt files
cp -f *.cub /nfs/home/hashmimu/calculations/orca_calcs/molecule  # Added this line for copying generated cub files
cp -f *.xyz /nfs/home/hashmimu/calculations/orca_calcs/molecule  # Added this line for copying generated xyz files
#---- end ORCA 6.1.0 specific part ----

#Delete the files from scratch
rm -rf /nfs/scratch/hashmimu/$SLURM_JOBID

• Below is the input file CH3I_opt.inp that is used in the above script.

%MaxCore 1000
%pal nprocs 16 end
# Optimization of CH3I
!B3LYP NoAutoStart TightSCF RIJCOSX def2-SVP def2/J def2-SVP/C 
%basis
NewECP I "def2-ECP" end # Define ECP for Iodine atom
end

* xyz 0 1
 C                  0.00000000    0.00000000   -1.79947500
 H                  0.00000000    1.03191700   -2.12804700
 H                 -0.89366600   -0.51595800   -2.12804700
 H                  0.89366600   -0.51595800   -2.12804700
 I                  0.00000000    0.00000000    0.32417000
*