Study of coulomb explosion and dissociation channels in dicationic argon clusters: a study based on stochastic optimization

Guha, Satyajit; Ray, Somrita; Chaudhury, Pinaki

doi:10.1007/s11224-011-9796-x

Cited by 16 publications

(9 citation statements)

References 36 publications

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“…A competition thus results and it is seen that only above a particular size of n = n c (critical size), does the stabilizing forces outweigh the repulsion and the cluster remains intact without dissociating. [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45] The cut-off limit or critical size is lowest for Xe and highest for Ar. This is expected since the polarizability of these noble gas atoms decrease in the following order Xe > Kr > Ar.…”

Section: Introductionmentioning

confidence: 99%

A parallel tempering based study of Coulombic explosion and identification of dissociating fragments in charged noble gas clusters

Talukder

Sen

Neogi

et al. 2013

The Journal of Chemical Physics

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In this communication, we would like to test the feasibility of a parallel tempering based study of dissociation in dicationic noble gas clusters, namely, Ar(n)(2+), Kr(n)(2+), and Xe(n)(2+), where "n" is the size of the cluster units. We would like to find out the correct limit for sizes of each of these systems, above which the clusters stay intact as a single unit and does not dissociate into fragments by the process of Coulomb explosion. Moreover, we would also like to, for a specific case, i.e., Ar(n)(2+), study in detail the fragmentation patterns and point out the switchover from the non-fission way to the fission mechanism of dissociation. In all these calculations, we would like to analyse, how close we are in our predictions with that of experimental results. As a further check on the dissociating patterns found out by parallel tempering, we also conduct basin hopping based study on representative sizes of the clusters and find that parallel tempering, as used for this present work as an optimizer, is able to predict correct features when compared with other celebrated methods like the basin hopping algorithm.

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Section: Introductionmentioning

confidence: 99%

A parallel tempering based study of Coulombic explosion and identification of dissociating fragments in charged noble gas clusters

Talukder

Sen

Neogi

et al. 2013

The Journal of Chemical Physics

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“…SA, since its proposition as a method, back in 1983, has been used extensively as a serious optimization tool in solving problems of chemistry and physics. [50][51][52][53][54][55][56][57][58][59] In this SA algorithm, the cost function is evaluated at each SA step. If cost function decreases, the move is accepted right away.…”

Section: Initialization Time Propagation Flux Analysis and Optmentioning

confidence: 99%

Selective bond breaking mediated by state specific vibrational excitation in model HOD molecule through optimized femtosecond IR pulse: A simulated annealing based approach

Shandilya

Sen

Sahoo

et al. 2013

The Journal of Chemical Physics

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The selective control of O-H/O-D bond dissociation in reduced dimensionality model of HOD molecule has been explored through IR+UV femtosecond pulses. The IR pulse has been optimized using simulated annealing stochastic approach to maximize population of a desired low quanta vibrational state. Since those vibrational wavefunctions of the ground electronic states are preferentially localized either along the O-H or O-D mode, the femtosecond UV pulse is used only to transfer vibrationally excited molecule to the repulsive upper surface to cleave specific bond, O-H or O-D. While transferring from the ground electronic state to the repulsive one, the optimization of the UV pulse is not necessarily required except specific case. The results so obtained are analyzed with respect to time integrated flux along with contours of time evolution of probability density on excited potential energy surface. After preferential excitation from [line]0, 0> ([line]m, n> stands for the state having m and n quanta of excitations in O-H and O-D mode, respectively) vibrational level of the ground electronic state to its specific low quanta vibrational state ([line]1, 0> or [line]0, 1> or [line]2, 0> or [line]0, 2>) by using optimized IR pulse, the dissociation of O-D or O-H bond through the excited potential energy surface by UV laser pulse appears quite high namely, 88% (O-H ; [line]1, 0>) or 58% (O-D ; [line]0, 1>) or 85% (O-H ; [line]2, 0>) or 59% (O-D ; [line]0, 2>). Such selectivity of the bond breaking by UV pulse (if required, optimized) together with optimized IR one is encouraging compared to the normal pulses.

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“…In the present work, we study the cutoff limit

n_{normalc}

of dicationic pristine

{Ar}_{N}

and

{Xe}_{N}

as well as for mixed

{Ar}_{M} {Xe}_{N}

clusters. Experimental evidence of cutoff limit for suppression of CE do exist for

{(Ar)}_{N}^{2 +}, {(Xe)}_{N}^{2 +}

as well as

{(Kr)}_{N}^{2 +}

systems . Mass‐spectrometric data do provide us with this important information.…”

Section: Introductionmentioning

confidence: 99%

“…Theoretically there has been attempts to understand CE using diverse techniques, mainly focused around simulation studies. Genetic Algorithm Simulated Annealing and Molecular Dynamics Simulation techniques have been used in one study of CE in dicationic noble gas clusters. A key issue, as we have already mentioned, is the use of a right PES.…”

Section: Introductionmentioning

confidence: 99%

Predicting stability limits for pure and doped dicationic noble gas clusters undergoing coulomb explosion: A parallel tempering based study

Ghorai

Chaudhury

2017

J Comput Chem

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We have used a replica exchange Monte-Carlo procedure, popularly known as Parallel Tempering, to study the problem of Coulomb explosion in homogeneous Ar and Xe dicationic clusters as well as mixed Ar-Xe dicationic clusters of varying sizes with different degrees of relative composition. All the clusters studied have two units of positive charges. The simulations reveal that in all the cases there is a cutoff size below which the clusters fragment. It is seen that for the case of pure Ar, the value is around 95 while that for Xe it is 55. For the mixed clusters with increasing Xe content, the cutoff limit for suppression of Coulomb explosion gradually decreases from 95 for a pure Ar to 55 for a pure Xe cluster. The hallmark of this study is this smooth progression. All the clusters are simulated using the reliable potential energy surface developed by Gay and Berne (Gay and Berne, Phys. Rev. Lett. 1982, 49, 194). For the hetero clusters, we have also discussed two different ways of charge distribution, that is one in which both positive charges are on two Xe atoms and the other where the two charges are at a Xe atom and at an Ar atom. The fragmentation patterns observed by us are such that single ionic ejections are the favored dissociating pattern. © 2017 Wiley Periodicals, Inc.

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Study of coulomb explosion and dissociation channels in dicationic argon clusters: a study based on stochastic optimization

Cited by 16 publications

References 36 publications

A parallel tempering based study of Coulombic explosion and identification of dissociating fragments in charged noble gas clusters

A parallel tempering based study of Coulombic explosion and identification of dissociating fragments in charged noble gas clusters

Selective bond breaking mediated by state specific vibrational excitation in model HOD molecule through optimized femtosecond IR pulse: A simulated annealing based approach

Predicting stability limits for pure and doped dicationic noble gas clusters undergoing coulomb explosion: A parallel tempering based study

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