Open Quantum, Inc. — Home of MRSF-TDDFT

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

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

01 · Expanding the reach of quantum theory

Next-generation quantum theories

MRSF-TDDFT and its variants extend ground- and excited-state calculations to bond breaking, diradicals, conical intersections, and singlet fission.

Research preview nc-CV-MRSF-TDDFT, MRSF-PP, and QMRSF-DK are in development. Supported calculations vary by method.

Explore OpenQP theories

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.

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

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

Analytic gradients and nonadiabatic couplings connect electronic states with molecular motion. Spin–orbit coupling describes intersystem crossing. OpenQP also supports 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 water environment · original molecular panel from Mazaherifar et al., *Faraday Discussions* (2026).

03 · Connected molecular simulations

From electronic states to dynamics

Combine geometry optimization, OpenMM-based QM/MM, and molecular dynamics in OpenQP. Follow excited states through MRSF surface hopping, including spin–orbit-coupled dynamics.

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

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

See what’s coming

OpenQP—The start of next-generation quantum theories.

Next-generation quantum theories

TRXAS

TRPES

ISC by SOC

Beyond energies

From electronic states to dynamics

GPU acceleration

OpenQPThe start of next-generation quantum theories.