ORCA: Get Started with ORCA

ORCA, one of the fastest computational chemistry software in the world!

ORCA is a general-purpose software for quantum chemistry with specific emphasis on spectroscopic properties and molecular properties of open-shell molecules. It is flexible, efficient, fast, and easy-to-use. ORCA features a wide variety of standard quantum chemical methods ranging from semi-empirical methods to DFT to single- and multireference correlated ab initio methods such as coupled-cluster (CC) theory. It can also treat environmental and relativistic effects. ORCA provides a free license for academic users and institutes under the agreement of EULA.

Download

The current version of ORCA (on the day of writing this post) is 4.1.0.

Go to https://orcaforum.kofo.mpg.de
Register account
Sign in and click on Download (the icon is at the top left of the website)
Agree with EULA
Choose the tarball of ORCA that is most appropriate with your OS and platform.
Download the tarball file to your machine

Installation

1. Uncompress the ORCA's tarball. For example, orca_4_1_0_linux_x86-64_openmpi313.tar.xz

$ tar -xvf orca_4_1_0_linux_x86-64_openmpi313.tar.xz

2. There will be a directory called orca_4_1_0_linux_x86-64_openmpi313

$ ls

orca_4_1_0_linux_x86-64_openmpi313

3. All sub-routine executables of ORCA are in this directory. So ORCA is ready-to-use! No need to compile anything here.

$ ls

autoci_ficmrci_ddci2_sigma autoci_rhf_poly12_sigma orca_cpcasscf orca_pc_mpi

autoci_ficmrci_ddci3_sigma autoci_rhf_poly14_sigma orca_cpscf orca_plot

autoci_ficmrci_ddci3_sigma_cosx autoci_rhf_poly1_sigma orca_cpscf_mpi orca_plot_mpi

autoci_ficmrci_ddci4_density autoci_rohf_cisd_product orca_eca orca_pltvib

autoci_ficmrci_ddci4_product autoci_rohf_denom_BO orca_ecplib orca_pnmr

autoci_ficmrci_ddci4_spindensity autoci_rohf_denom_DYALL orca_eprnmr orca_pnmr_mpi

autoci_ficmrci_ddci4_transitiondensity autoci_rohf_denom_EPSILON orca_eprnmr_mpi orca_pop

autoci_ficmrci_ddci4_transitionoverlap autoci_rohf_norm_contra_cov orca_esd orca_pop_mpi

autoci_ficmrci_sigma autoci_rohf_poly12_sigma orca_euler orca_rel

autoci_fic_qsddci3_rshift autoci_rohf_poly1_sigma orca_exportbasis orca_rel_mpi

autoci_fic_qsddci3_sigma autoci_uhf_denom_EPSILON orca_fci orca_rocis

autoci_iprocisd_denom_EPSILON autoci_uhf_poly14_sigma orca_fitpes orca_rocis_mpi

autoci_iprocisd_denom_EPSILON_mpi autoci_uhf_poly1_sigma orca_fragovl orca_scf

autoci_iprocisd_denom_somo contrib orca_gstep orca_scfgrad

autoci_iprocisd_denom_somo_mpi orca orca_gtoint orca_scfgrad_mpi

autoci_iprocisd_density orca_2aim orca_gtoint_mpi orca_scfhess

autoci_iprocisd_density_mpi orca_2mkl orca_loc orca_scfhess_mpi

autoci_iprocisd_sigma_alpha orca_anoint orca_mapspc orca_scf_mpi

autoci_iprocisd_sigma_alpha_doublet orca_anoint_mpi orca_mcrpa orca_soc

autoci_iprocisd_sigma_alpha_doublet_mpi orca_asa orca_mcrpa_mpi orca_soc_mpi

autoci_iprocisd_sigma_alpha_mpi orca_autoci orca_md orca_util

autoci_iprocisd_sigma_beta orca_autoci_mpi orca_mdci orca_util_mpi

autoci_iprocisd_sigma_beta_mpi orca_blockf orca_mdci_mpi orca_vib

autoci_iprocisd_sigma_somo orca_casscf orca_mergefrag orca_vpot

autoci_iprocisd_sigma_somo_mpi orca_casscf_mpi orca_mm otool_anmr

autoci_rhf_cisd_density1 orca_cclib orca_mp2 otool_dftd4

autoci_rhf_cisd_der orca_chelpg orca_mp2_mpi otool_gcp

autoci_rhf_cisd_product orca_ciprep orca_mrci otool_xtb

autoci_rhf_denom_BO orca_cipsi orca_mrci_mpi Third_Party_Licenses_Academic_4.1.pdf

autoci_rhf_denom_DYALL orca_cipsi_mpi orca_ndoint

autoci_rhf_denom_EPSILON orca_cis orca_numfreq

autoci_rhf_norm_contra_cov orca_cis_mpi orca_pc

4. Edit .bashrc and ddd ORCA directory to your PATH environment variable. Then activate .bashrc again.

$ vi $HOME/.bashrc

export PATH="/full/path/of/orca_4_1_0_linux_x86-64_openmpi313":$PATH

$ source $HOME/.bashrc

5. Install the OpenMPI as its version must match with the tarball of ORCA you downloaded. In my case, I need OpenMPI 3.1.3.

Read this post for installing of OpenMPI

Running ORCA

ORCA must be called with its absolute path!

Example input file, called test.inp

! B3LYP def2-SVP Opt

# B3LYP is here the method (DFT functional), def2-SVP the basis set and Opt is the jobtype (geometry optimization).

# Order of the keywords is not important.

*xyz 0 1

H 0.0 0.0 0.0

H 0.0 0.0 1.0

*

On Linux Standalone Machine

~/orca_4_1_0_linux_x86-64_openmpi313/orca test.inp

or print stdout to output file called test.out

~/orca_4_1_0_linux_x86-64_openmpi313/orca test.inp >& test.out &

On Linux Cluster using Job Queue System

For Grid Engine

#!/bin/bash

#$ -S /bin/sh

#$ -N "TEST-ORCA"

#$ -cwd

#$ -j y

#$ -m be

#$ -M rangsiman1993@gmail.com

#$ -pe mpifill 8

#$ -l h_vmem=3G

#$ -V

module purge

export PATH="/home/rangsiman/.openmpi/bin/":$PATH

export LD_LIBRARY_PATH="/home/rangsiman/.openmpi/lib/":$LD_LIBRARY_PATH

export OMP_NUM_THREADS=1

ORCA="/home/rangsiman/orca_4_1_0_linux_x86-64_openmpi313/orca"

$ORCA test.inp >& test.out &

For PBS

#!/bin/bash

#PBS -l select=1:mpiprocs=8

#PBS -l walltime=100:00:00

#PBS -N TEST-ORCA

#PBS -m bea

#PBS -M rangsiman1993@gmail.com

#PBS -V

#PBS -q short

cd $PBS_O_WORKDIR

module purge

export PATH="/home/rangsiman/.openmpi/bin/":$PATH

export LD_LIBRARY_PATH="/home/rangsiman/.openmpi/lib/":$LD_LIBRARY_PATH

export OMP_NUM_THREADS=1

ORCA="/home/rangsiman/orca_4_1_0_linux_x86-64_openmpi313/orca"

$ORCA test.inp >& test.out &

Output file

ORCA generates many temporary output file during calculations.

$ ls

test.engrad test.gbw test.inp test.opt test.out test.prop test_property.txt test.trj test.xyz

A portion of ORCA output file.

*****************

* O R C A *

*****************

--- An Ab Initio, DFT and Semiempirical electronic structure package ---

#######################################################

# -***- #

# Department of theory and spectroscopy #

# Directorship: Frank Neese #

# Max Planck Institute fuer Kohlenforschung #

# Kaiser Wilhelm Platz 1 #

# D-45470 Muelheim/Ruhr #

# Germany #

# #

# -***- #

#######################################################

Program Version 4.1.0 - RELEASE -

With contributions from (in alphabetic order):

Daniel Aravena : Magnetic Properties

Michael Atanasov : Ab Initio Ligand Field Theory

Alexander A. Auer : GIAO ZORA

Ute Becker : Parallelization

Giovanni Bistoni : ED, Open-shell LED

Martin Brehm : Molecular dynamics

Dmytro Bykov : SCF Hessian

Vijay G. Chilkuri : MRCI spin determinant printing

Dipayan Datta : RHF DLPNO-CCSD density

...

Rangsiman Ketkaew