The multiconfigurational time‐dependent Hartree (MCTDH) approximation to the time‐dependent Schrodinger equation is tested for a realistic three‐dimensional example, the photodissociation of NOCl. The working equations of the MCTDH scheme introduced earlier are discussed in some detail. A computational scheme is presented which allows for efficient numerical MCTDH calculations. This scheme is applied to the photodissociation of NOCl after excitation to the S1 surface. The results are compared to the results of an exact wave‐packet dynamics calculation. Fast convergence of the MCTDH results toward the exact one is found as the number of configurations is increased. The computation times of the MCTDH calculations are found to be much shorter than those of the exact calculation. Even MCTDH calculations including sufficiently many configurations for a fully converged (quasiexact) description require over two orders of magnitude less CPU time than an exact calculation. The so‐called ‘‘natural populations’’ tha...

Wave‐packet dynamics within the multiconfiguration Hartree framework: General aspects and application to NOCl

Cyanogen iodide (ICN) is photodissociated at 249 nm. The CN X 2Σ+ photofragment is probed by sub‐Doppler laser‐induced fluorescence (LIF), allowing the extraction of recoil velocity anisotropies and branching ratios to the two iodine atom spin–orbit states I(2P1/2) and I(2P3/2) as a function of the CN (v=0) rotational state. The quantum yield for I(2P1/2) production ΦI* is found to be 43%±3%, in excellent agreement with the recent diode laser spectroscopic measurement of Hess and Leone. The population of the F1 and F2 spin–rotation doublet components shows nonstatistical behavior over a wide range of N for both I atom spin–orbit state exit channels. The results suggest that trajectories leading to I(2P1/2) evolve on an essentially collinear surface; the CN fragments being found in low rotational levels with almost limiting values of the system anisotropy parameter (β=1.85 to 1.9). This value of β yields an estimate for the dissociative lifetime [CN X 2Σ+v=0, N=0; I(2P1/2)] of 90±15 fs at this photolysis w...

Evidence for three interacting potential energy surfaces in the photodissociation of ICN at 249 nm

The electronic absorption spectrum of NOCl in the region 620–180 nm is assigned by using vector properties of the NO photofragment and the results of ab initio calculations at the CI level. In assigning the electronic spectrum, we take into account the recoil anisotropy, rotational alignment, and Λ‐doublet populations of NO, as well as the calculated vertical excitation energies, oscillator strengths, and the nature of the orbitals involved in the transitions. In the experiments, we use expansion‐cooled samples and measure the recoil anisotropy parameters from the Doppler profiles of selected NO A 2Σ+←X 2Π rotational lines. The alignment parameters and Λ‐doublet populations are derived from the rotational spectra using different laser polarizations and excitation–detection geometries. The theoretical calculations treat all low‐lying singlet and triplet states. The calculations yield least energy paths for the excited states, with optimized rNO and ClNO angle as a function of rClN, as well as the angular dependences of the potentials and oscillator strengths of the singlet–singlet transitions. The following assignments are proposed for the main absorption bands: (1) E band—T1(1 3A‘)←S0(1 1A’); the transition borrows intensity by mixing with remote singlet states, predominantly the 4 1A’ state; (2) D and C bands—S1(1 1A‘)←S0(1 1A’); the C band corresponds to excitation of ν’1 in S1; (3) B band—S3(2 1A’)←S0(1 1A’); (4) A band—S5(4 1A’)→S0(1 1A’). The assignments proposed here are in full agreement with all the experimental observations and the results of the calculations. Despite the shallow minima calculated for the T1 and S1 surfaces, dissociation on all the surfaces is fast, and the implications of the results to the dissociation dynamics are discussed.

The electronic spectrum of NOCl: Photofragment spectroscopy, vector correlations, and ab initio calculations

We present the results of a three‐dimensional wave packet study on the photodissociation of ClNO through excitation of the first singlet state S1. The calculations employ an ab initio potential energy surface depending on the Cl–N and N–O bond coordinates and the ClNO bending angle. By expanding the wave packet in terms of the eigenfunctions of the NO rotor, the time‐dependent Schrodinger equation is transformed into a coupled set of 60 two‐dimensional partial differential equations which are solved by discretization on a grid. The wave packet yields the absorption spectrum and all partial dissociation cross sections for producing the NO fragment in a particular vibrational–rotational state (nj). The photodissociation of ClNO via the S1 state is a relatively fast process and the necessary propagation time is on the order of 50 fs. The calculated data agree well with recent experimental results. For the first time, we can directly compare the wavelength dependence of partial photodissociation cross section...

The direct photodissociation of ClNO(S1): An exact three‐dimensional wave packet analysis

Photofragment vector correlations measured by sub-doppler 2+1 laser-induced fluorescence spectroscopy

NO(X 2Π) rotational distributions from the photodissociation of NOCl and NOBr at 450 and 470 nm

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

A.E. Bruno

Author Tools

Chat about Author

Papers

NO(X 2Π) rotational distributions from the photodissociation of NOCl and NOBr at 450 and 470 nm