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Real science backed by cutting-edge quantum theories.

Home of MRSF-TDDFT

GFP protein ribbons with the CRO A66 chromophore at its original position; PDB 1EMA
Separate enlarged face-on view of the same 22-atom GFP chromophore in ball-and-stick representation

GFP chromophoreEnlarged view

OpenQPThe start of next-generation quantum theories.

Upcoming version 1.4.0 with new cutting-edge quantum technologies!

Why OpenQP?

Two pentacene molecules rendered from PubChem 3D coordinates in an illustrative stacked arrangement

Singlet
Fission

Pentacene pair · PubChem 3D monomers, illustrative arrangement. Related research: ChemRxiv (2026).

01 · Expanding the reach of quantum theory

Next-generation theories.
Broader scientific possibilities.

MRSF-TDDFT and its expanding family—including nc-CV-MRSF-TDDFT, MRSF-PP, and QMRSF-DK—bring new possibilities to ground- and excited-state quantum chemistry.

Bond breaking · Diradicals · Conical intersections · Singlet fission

Research preview nc-CV-MRSF-TDDFT, MRSF-PP, and QMRSF-DK are research developments; availability and supported calculations differ by method.

Explore OpenQP theories

TRXAS

Author source TRXAS spectrum showing X-ray photon energy against time with its original intensity scale
Time-resolved X-ray absorption · author source spectrum, panel c.

TRPES

Author source GFP chromophore TRPES spectrum showing electron binding energy against time
Time-resolved photoelectron spectrum · GFP chromophore, author source figure.

ISC by SOC

SOC-MRSF author graphical abstract illustrating internal conversion and intersystem crossing among electronic states
Spin–orbit coupling · Komarov et al., JCTC (2023), author graphical abstract.

02 · Properties and couplings

Beyond energies.
Understand molecular behavior.

Analytic energy gradients, analytic nonadiabatic couplings, and spin–orbit coupling connect electronic structure with molecular motion and photochemistry.

Molecular geometries · Internal conversion · Intersystem crossing

Explore further with MRSF-EKT Dyson orbitals and X-ray absorption calculations.

Discover MRSF capabilities
Three-dimensional periodic water box with many surrounding water molecules and a highlighted central QM water molecule, from the OpenQP multiscale dynamics study

Periodic
QM/MM

Periodic water environment · original molecular panel from Mazaherifar et al., Faraday Discussions (2026).

03 · Connected molecular simulations

One platform.
From electronic states to molecular dynamics.

Connect electronic-structure calculations, geometry optimization, QM/MM, molecular dynamics, and nonadiabatic dynamics within OpenQP.

Follow MRSF electronic states through surface-hopping trajectories, including spin–orbit-coupled dynamics, and model molecular environments with OpenMM-based QM/MM.

Explore simulation tutorials
DNA double helix from PDB 1BNA with backbone guides and selected residues in ball-and-stick
DNA · PDB 1BNA. Molecular visualization; GPU acceleration remains in development.

04 · Looking ahead · In development

GPU acceleration is on the horizon.

GPU acceleration is in development, targeting demanding electronic-structure calculations and molecular simulations.

See what’s coming