A beyond Born–Oppenheimer treatment of C6H6+ radical cation for diabatic surfaces: Photoelectron spectra of its neutral analog using time-dependent discrete variable representation

2021 ◽  
Vol 154 (9) ◽  
pp. 094306
Author(s):  
Soumya Mukherjee ◽  
Satyam Ravi ◽  
Koushik Naskar ◽  
Subhankar Sardar ◽  
Satrajit Adhikari
Keyword(s):  
Radical Cation ◽  
Photoelectron Spectra ◽  
Time Dependent ◽  
Discrete Variable ◽  
Discrete Variable Representation ◽  
Variable Representation

Beyond Born-Oppenheimer Based Diabatic Surfaces of 1,3,5-C6H3F3+ to Generate the Photoelectron Spectra Using Time-Dependent Discrete Variable Representation Approach

2021 ◽  
Author(s):  
Soumya Mukherjee ◽  
Satyam Ravi ◽  
Joy Dutta ◽  
Subhankar Sardar ◽  
Satrajit Adhikari
Keyword(s):  
Potential Energy ◽  
Potential Energy Surfaces ◽  
Photoelectron Spectra ◽  
Time Dependent ◽  
Two Dimensional ◽  
Discrete Variable ◽  
Discrete Variable Representation ◽  
Energy Surfaces ◽  
Variable Representation

In this article, Beyond Born-Oppenheimer (BBO) treatment is implemented to construct diabatic potential energy surfaces (PESs) of 1,3,5-C6H3F3+ over a series [eighteen (18)] of two-dimensional (2D) nuclear planes constituted with...

NEARLY LINEAR SCALABILITY OF TIME-DEPENDENT DISCRETE VARIABLE REPRESENTATION (TDDVR) METHOD FOR THE DYNAMICS OF MULTI-SURFACE MULTI-MODE HAMILTONIAN

2013 ◽  
Vol 12 (05) ◽  
pp. 1350042 ◽  
Author(s):  
BASIR AHAMED KHAN ◽  
SUBHANKAR SARDAR ◽  
TAPAS SAHOO ◽  
PRANAB SARKAR ◽  
SATRAJIT ADHIKARI
Keyword(s):  
Quantum Dynamics ◽  
Radiative Decay ◽  
Electronic States ◽  
Photoelectron Spectra ◽  
Time Dependent ◽  
Basis Set ◽  
Discrete Variable ◽  
Discrete Variable Representation ◽  
Variable Representation ◽  
Multi Mode

Time-Dependent Discrete Variable Representation (TDDVR) method was implemented by involving "classical" trajectories on each degrees of freedom (DOF) for the dynamics of multi-surface multi-mode Hamiltonian. The major focus of this article is to explore the efficiency of the serial and parallelized TDDVR algorithm for relatively large dimensional quantum dynamics in presence of non-adiabaticity among the electronic states. As a model system, the complex photoelectron spectra and non-radiative decay dynamics of trifluoroacetonitrile radical cation ( CF3CN+ ) are theoretically simulated with the aid of such parallelized algorithm, where the five lowest electronic states (X2E, A2A1, B2A2, C2A1, and D2E) of the Hamiltonian are interconnected through several conical intersections in the vicinity of Frank–Condon region with twelve (12) active vibrational modes. The Jahn–Teller splitting of the X2E and D2E states makes the coupled five-surface system to a more challenging quantum dynamical seven-surface twelve-mode model. The results obtained from the TDDVR approach show very good agreement with the profiles of both Multi Configuration Time-Dependent Hartree (MCTDH) methodology and experimental technique, where its' sequencial and parallelized algorithm depict closely linear scalability with the increasing number of basis set vis-a-vis DOFs.

Imaginary-Time Time-Dependent Density Functional Calculation of Excited States of Atoms Using CWDVR Approach

2021 ◽  
Vol 323 ◽  
pp. 14-20
Author(s):  
Naranchimeg Dagviikhorol ◽  
Munkhsaikhan Gonchigsuren ◽  
Lochin Khenmedekh ◽  
Namsrai Tsogbadrakh ◽  
Ochir Sukh
Keyword(s):  
Excited States ◽  
Density Functional ◽  
Time Dependent ◽  
Discrete Variable ◽  
Coulomb Wave Function ◽  
Discrete Variable Representation ◽  
Density Functional Calculation ◽  
Imaginary Time ◽  
Sham Equation ◽  
Variable Representation

We have calculated the energies of excited states for the He, Li, and Be atoms by the time dependent self-consistent Kohn Sham equation using the Coulomb Wave Function Discrete Variable Representation CWDVR) approach. The CWDVR approach was used the uniform and optimal spatial grid discretization to the solution of the Kohn-Sham equation for the excited states of atoms. Our results suggest that the CWDVR approach is an efficient and precise solutions of excited-state energies of atoms. We have shown that the calculated electronic energies of excited states for the He, Li, and Be atoms agree with the other researcher values.

TIME-DEPENDENT QUANTUM MECHANICAL TREATMENT OF He–CO INELASTIC SCATTERING

2004 ◽  
Vol 03 (03) ◽  
pp. 291-303 ◽  
Author(s):  
SINAN AKPINAR ◽  
NIYAZI BULUT ◽  
FAHRETTIN GOGTAS
Keyword(s):  
Wave Packet ◽  
Mechanical Treatment ◽  
Total Angular Momentum ◽  
Time Dependent ◽  
Quantum Mechanical ◽  
Discrete Variable ◽  
Discrete Variable Representation ◽  
Quantum Mechanical Treatment ◽  
Quantum Wave ◽  
Variable Representation

The state-to-state and state-to-all reaction probabilities for He + CO (v,j)→ He + CO (v',j') reaction at zero total angular momentum have been calculated by using a time-dependent quantum wave packet method. The time-dependent method used is based on Fourier Grid and Discrete Variable Representation (DVR) techniques. The time-dependent propagation of the wave packet is accomplished by an expansion in terms of modified complex chebyshev polynomials. The results show that the He + CO reaction is not reactive in the studied energy range.

Classical blended quantum formulation of the parallel TDDVR method to the dynamics on furan

2015 ◽  
Vol 14 (05) ◽  
pp. 1550039 ◽  
Author(s):  
Subhankar Sardar
Keyword(s):  
Photoelectron Spectra ◽  
Time Dependent ◽  
Discrete Variable Representation ◽  
Molecular Systems ◽  
Dynamical Simulation ◽  
Dynamical Simulations ◽  
Speed Up ◽  
Dynamical Method ◽  
Variable Representation ◽  
Good Agreement

A major portion (∼98%) of the quantum-classical molecular dynamics approach, namely, Time-Dependent Discrete Variable Representation (TDDVR) method, is recently parallelized using shared-memory parallelization scheme with the aim of performing dynamics on relatively large molecular systems. Therefore, we have chosen the furan as a model system for dynamical simulation. Four lowest singlet excited electronic states 1A2(3s), 1B2(V), 1A1(V*), and 1B1(3p) of furan are vibronically coupled through several conical intersections in the vicinity of Frank-Condon region. The major focus of the present paper is to explore the efficiency of our newly implemented parallelized TDDVR algorithm to perform dynamics on large dimensional quantum systems in vibronically coupled electronic manifold. The present version of parallelized TDDVR algorithm show closely linear speed up with increasing number of computing processors. As a significant speed up is achieved by cycling in the correct way over arrays, all dynamical simulations are performed within a reasonable wall clock time. The photoelectron spectra calculated by the TDDVR method show peak by peak correspondence with the experimental spectra. The TDDVR calculated quantum-classical dynamical outcomes, viz., population and photoelectron spectra, etc. show good agreement with the findings of the well-established quantum dynamical method, i.e. Multi Configuration Time-Dependent Hartree (MCTDH) approach.

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