# RhoDyn: A ρ-TD-RASCI Framework to Study Ultrafast Electron Dynamics in Molecules.
> 分子の超高速電子ダイナミクス解析のための密度行列ベースTD-RASCIフレームワーク「RhoDyn」の開発


## Abstract

This work introduces RhoDyn, a computational module integrated into the OpenMOLCAS package, designed to investigate ultrafast electron dynamics using a density-matrix-based time-dependent restricted active space configuration interaction (ρ-TD-RASCI) approach. The framework accommodates spin-orbit coupling, incorporates nuclear vibrational effects modeled as a vibrational heat bath, and handles (auto)ionization processes. Application examples include simulations of linear L-edge X-ray absorption spectra of a titanium complex, high harmonic generation in the hydrogen molecule, ultrafast charge migration in benzene and iodoacetylene, and spin-flip dynamics in core-excited states of iron complexes. The paper details both the theoretical foundations and the practical program workflow.

### Mechanism

The ρ-TD-RASCI formalism integrates spin-orbit coupling, nuclear vibrational heat-bath effects, and autoionization within a density-matrix framework to enable quantum-chemical simulation of ultrafast electron dynamics in molecular systems.

## Bibliographic

- **Authors**: Kochetov V, Bokarev SI
- **Journal**: J Chem Theory Comput
- **Year**: 2022 (2022-01-11)
- **PMID**: [34965135](https://pubmed.ncbi.nlm.nih.gov/34965135/)
- **DOI**: [10.1021/acs.jctc.1c01097](https://doi.org/10.1021/acs.jctc.1c01097)
- **Study type**: other
- **Delivery route**: not specified
- **Effect reported**: not assessed

## Delivery context

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)

---

> **Cite as**: H2 Papers — PMID 34965135. https://h2-papers.org/en/papers/34965135
> **Source**: PubMed PMID [34965135](https://pubmed.ncbi.nlm.nih.gov/34965135/)