scholarly journals Crossing Networks: Competition and Design

2006 ◽  
Author(s):  
Hans Degryse ◽  
Mark Van Achter ◽  
Gunther Wuyts
Keyword(s):  
Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2230
Author(s):  
Ziyue He ◽  
Ruidi Xue ◽  
Yibo Lei ◽  
Le Yu ◽  
Chaoyuan Zhu

Multi-state n-electron valence state second order perturbation theory (MS-NEVPT2) was utilized to reveal the photorelaxation pathways of 4-(N,N-dimethylamino)-4′-nitrostilbene (DANS) upon S1 excitation. Within the interwoven networks of five S1/S0 and three T2/T1 conical intersections (CIs), and three S1/T2, one S1/T1 and one S0/T1 intersystem crossings (ISCs), those competing nonadiabatic decay pathways play different roles in trans-to-cis and cis-to-trans processes, respectively. After being excited to the Franck–Condon (FC) region of the S1 state, trans-S1-FC firstly encounters an ultrafast conversion to quinoid form. Subsequently, the relaxation mainly proceeds along the triplet pathway, trans-S1-FC → ISC-S1/T2-trans → CI-T2/T1-trans → ISC-S0/T1-twist → trans- or cis-S0. The singlet relaxation pathway mediated by CI-S1/S0-twist-c is hindered by the prominent energy barrier on S1 surface and by the reason that CI-S1/S0-trans and CI-S1/S0-twist-t are both not energetically accessible upon S1 excitation. On the other hand, the cis-S1-FC lies at the top of steeply decreasing potential energy surfaces (PESs) towards the CI-S1/S0-twist-c and CI-S1/S0-DHP regions; therefore, the initial twisting directions of DN and DAP moieties determine the branching ratio between αC=C twisting (cis-S1-FC → CI-S1/S0-twist-c → trans- or cis-S0) and DHP formation relaxation pathways (cis-S1-FC → CI-S1/S0-DHP → DHP-S0) on the S1 surface. Moreover, the DHP formation could also take place via the triplet relaxation pathway, cis-S1-FC → ISC-S1/T1-cis → DHP-T1 → DHP-S0, however, which may be hindered by insufficient spin-orbit coupling (SOC) strength. The other triplet pathways for cis-S1-FC mediated by ISC-S1/T2-cis are negligible due to the energy or geometry incompatibility of possible consecutive stepwise S1 → T2 → T1 or S1 → T2 → S1 processes. The present study reveals photoisomerization dynamic pathways via conical intersection and intersystem crossing networks and provides nice physical insight into experimental investigation of DANS.


2013 ◽  
Vol 8 (3) ◽  
pp. 16-39 ◽  
Author(s):  
Vladimir Markov ◽  
Tito Ingargiola
Keyword(s):  

2000 ◽  
Vol 55 (5) ◽  
pp. 2071-2115 ◽  
Author(s):  
Terrence Hendershott ◽  
Haim Mendelson

2019 ◽  
Vol 100 ◽  
pp. 131-151
Author(s):  
Jana Bielagk ◽  
Ulrich Horst ◽  
Santiago Moreno-Bromberg

2014 ◽  
Vol 62 (5) ◽  
pp. 1179-1201 ◽  
Author(s):  
Philipp Afèche ◽  
Adam Diamant ◽  
Joseph Milner

2006 ◽  
Vol 1 (4) ◽  
pp. 453-469
Author(s):  
Hans Degryse ◽  
Mark Van Achter ◽  
Gunther Wuyts
Keyword(s):  

2018 ◽  
Author(s):  
Jana Bielagk ◽  
Ulrich Horst ◽  
Santiago Moreno-Bromberg

2002 ◽  
Vol 14 (9) ◽  
pp. 2043-2051 ◽  
Author(s):  
Boonyanit Mathayomchan ◽  
Randall D. Beer

A center-crossing recurrent neural network is one in which the null- (hyper) surfaces of each neuron intersect at their exact centers of symmetry, ensuring that each neuron's activation function is centered over the range of net inputs that it receives. We demonstrate that relative to a random initial population, seeding the initial population of an evolutionary search with center-crossing networks significantly improves both the frequency and the speed with which high-fitness oscillatory circuits evolve on a simple walking task. The improvement is especially striking at low mutation variances. Our results suggest that seeding with center-crossing networks may often be beneficial, since a wider range of dynamics is more likely to be easily accessible from a population of center-crossing networks than from a population of random networks.


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