Open Quantum Platform (OpenQP) is a quantum chemical platform featuring cutting-edge capabilities like Mixed-Reference Spin-Flip (MRSF)-TDDFT with an emphasis on open-source ecosystem.

• Autonomous Modules of Quantum Chemistry Theories for Easy Interoperability
• Flexible prototyping through a Python wrapper, PyOQP
• Ground and Excited State Properties by MRSF-TDDFT
• Nonadiabatic Coupling based on TLF Technology using MRSF-TDDFT
• New Exchange-Correlation Functionals of DTCAM series for MRSF-TDDFT
• Ground State Properties by HF and DFT theories
• Geometry Optimization, Transition State Search, and Conical Intersection Search by SciPy and DL-Find
• PyRAI2MD Integration to support Artificial Intelligence Ab Initio Molecular Dynamics
• LibXC Integration to support a variety of exchange-correlation functionals
• basis_set_exchange Integration to support a variety of basis sets
• libecpint Integration to support a variety of Effective Core Potentials
• Support for Molden File Format for visualization, compatible with many graphic software tools
• DFT-D4 Dispersion Correction
• OpenMP and MPI Parallelization and BLAS/LAPACK Optimization for high performance
• OpenTrustRegion library for stable SCF convergence
• MOKIT for adopting better initial guess from pyscf/ORCA

• Efficient electrostatic embedding QM/MM by ESPF QM/MM
• Spin-Orbit Coupling by Relativistic MRSF-TDDFT
• Ionization Potential/Electron Affinity by EKT-MRSF-TDDFT

• pip install openqp or
• Ready to Use Docker Image of openqp/openqp or
• Building from Source Files Using the Instructions Below.

• GCC, G++, Gfortran: Version >= 8
• CMake: Version >= 3.25
• cffi: Perform pip install cffi
• ninja (optional)
• MPI Library: OpenMPI For MPI Support. Consult detailed documentation for other MPI libraries

git clone https://github.com/Open-Quantum-Platform/openqp.git

cd openqp
pip install .

or

cd openqp
cmake -B build -G Ninja -DUSE_LIBINT=OFF -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ -DCMAKE_Fortran_COMPILER=gfortran -DCMAKE_INSTALL_PREFIX=. -DENABLE_OPENMP=ON -DLINALG_LIB_INT64=OFF
ninja -C build install
cd pyoqp
pip install .

cd openqp
cmake -B build -G Ninja -DUSE_LIBINT=OFF -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ -DCMAKE_Fortran_COMPILER=mpif90 -DCMAKE_INSTALL_PREFIX=. -DENABLE_OPENMP=ON -DLINALG_LIB_INT64=OFF -DENABLE_MPI=ON
ninja -C build install
cd pyoqp
pip install .

cd openqp
cmake -B build -DUSE_LIBINT=OFF -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ -DCMAKE_Fortran_COMPILER=mpif90 -DCMAKE_INSTALL_PREFIX=. -DENABLE_OPENMP=ON -DLINALG_LIB_INT64=OFF -DENABLE_MPI=ON
make -C build install
cd pyoqp
pip install .

• Use -DUSE_LIBINT=ON to replace the default ERI based on Rys Quadrature with libint.
• Use -DLINALG_LIB_INT64=OFF to ensure compatibility with third-party software like libdlfind compiled with 32-bit BLAS.

export OPENQP_ROOT=/path/to/openqp                           # Path to the Root of openqp
export OMP_NUM_THREADS=4                                     # The number of cores to be used for OpenMP runs
export LD_LIBRARY_PATH=$OPENQP_ROOT/lib:$LD_LIBRARY_PATH

Special Environmental Settings for MKL Math Library:

export MKL_INTERFACE_LAYER="@_MKL_INTERFACE_LAYER@"
export MKL_THREADING_LAYER=SEQUENTIAL

openqp --run_tests all     # Run all tests from all folders in examples

For OpenMP or sequential run:

openqp any_example_file.inp

For OpenMP and MPI run:

mpirun -np number_of_mpi openqp any_example_file.inp

For more in-depth information, visit:

• OpenQP Documentation

Easily create input files for OpenQP using our Web-based Input Generator.

If you use OpenQP in your research, please cite the following papers:

• Mironov V, Komarov K, Li J, Gerasimov I, Mazaheri M, Park W, Lashkaripour A, Oh M, Nakata H, Ishimura K, Huix-Rotllant M, Lee S, and Choi CH. "OpenQP: A Quantum Chemical Platform Featuring MRSF-TDDFT with an Emphasis on Open-source Ecosystem" Journal of Chemical Theory and Computation, 2024
• Park W, Komarov K, Lee S, and Choi CH. "Mixed-Reference Spin-Flip Time-Dependent Density Functional Theory: Multireference Advantages with the Practicality of Linear Response Theory." The Journal of Physical Chemistry Letters. 2023 Sep 28;14(39):8896-908.
• Lee S, Filatov M, Lee S, and Choi CH. "Eliminating Spin-Contamination of Spin-Flip Time-Dependent Density Functional Theory Within Linear Response Formalism by the Use of Zeroth-Order Mixed-Reference (MR) Reduced Density Matrix." The Journal of Chemical Physics, vol. 149, no. 10, 2018.
• Lee S, Kim EE, Nakata H, Lee S, and Choi CH. "Efficient Implementations of Analytic Energy Gradient for Mixed-Reference Spin-Flip Time-Dependent Density Functional Theory (MRSF-TDDFT)." The Journal of Chemical Physics, vol. 150, no. 18, 2019.

• Cheol Ho Choi, Kyungpook National University, South Korea, cheolho.choi@gmail.com, https://www.openqp.org
• Seunghoon Lee, Seoul National University, South Korea, seunghoonlee89@gmail.com
• Vladimir Mironov, vladimir.a.mironov@gmail.com
• Konstantin Komarov, constlike@gmail.com
• Jingbai Li, Hoffmann Institute of Advanced Materials, China, lijingbai2009@gmail.com
• Igor Gerasimov, i.s.ger@yandex.ru
• Hiroya Nakata, Fukui Institute for Fundamental Chemistry, Japan, nakata.hiro07@gmail.com
• Mohsen Mazaherifar, Kyungpook National University, South Korea, moh.mazaheri@gmail.com

See the separate LICENSE file.