scholarly journals Experimental and Computational Evidence of non-MEP Pathways in the Fragmentation and Rearrangement of Bicyclo[3.3.1] heptane Diazonium Ions

2021 ◽  
Author(s):  
Bastian Wulff ◽  
Patrick Sakrausky ◽  
Katrin Adamczyk ◽  
Nils Huse ◽  
Julia Rehbein
Keyword(s):  
Computational Chemistry ◽  
Stationary Point ◽  
Minimum Energy ◽  
Md Simulations ◽  
Point Analysis ◽  
Diazonium Ions ◽  
Energy Pathways

The non-minimum energy pathways on the fragmentation of bicyclic diazoniumions and subsequent carbocationic rearrangements has been studied by a combination of computational chemistry (MD simulations, IRC, stationary point analysis) and experiments (TR-IR and UV from ps to µs, NMR kinetics).<div><br></div>

scholarly journals Experimental and Computational Evidence of non-MEP Pathways in the Fragmentation and Rearrangement of Bicyclo[3.3.1] heptane Diazonium Ions

2021 ◽  
Author(s):  
Bastian Wulff ◽  
Patrick Sakrausky ◽  
Katrin Adamczyk ◽  
Nils Huse ◽  
Julia Rehbein
Keyword(s):  
Computational Chemistry ◽  
Stationary Point ◽  
Minimum Energy ◽  
Md Simulations ◽  
Point Analysis ◽  
Diazonium Ions ◽  
Energy Pathways

The non-minimum energy pathways on the fragmentation of bicyclic diazoniumions and subsequent carbocationic rearrangements has been studied by a combination of computational chemistry (MD simulations, IRC, stationary point analysis) and experiments (TR-IR and UV from ps to µs, NMR kinetics).<div><br></div>

scholarly journals Rock climbing: A local-global algorithm to compute minimum energy and minimum free energy pathways

2017 ◽  
Vol 147 (15) ◽  
pp. 152718 ◽  
Author(s):  
Clark Templeton ◽  
Szu-Hua Chen ◽  
Arman Fathizadeh ◽  
Ron Elber
Keyword(s):  
Free Energy ◽  
Minimum Energy ◽  
Minimum Free Energy ◽  
Rock Climbing ◽  
Global Algorithm ◽  
Energy Pathways

Structural stability of CmTin microclusters and nanoparticles: Molecular–dynamics simulations

2005 ◽  
Vol 1 (4) ◽  
pp. 204-209
Author(s):  
O.B. Malcıoğlu ◽  
Ş. Erkoç
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Binary Systems ◽  
Minimum Energy ◽  
Potential Energy Function ◽  
Md Simulations ◽  
Atomic Interactions ◽  
Dynamics Simulations ◽  
Three Body ◽  
Initial Geometry

The minimum energy structures of CmTin microclusters and nanoparticles have been investigated theoretically by performing molecular–dynamics (MD) simulations. Selected crystalline and completely random initial geometries are considered. The potential energy function (PEF) used in the calculations includes two– and three–body atomic interactions for C-Ti binary systems. Molecular–dynamics simulations have been performed at 1 K and 300 K. It has been found that initial geometry has a very strong influence on relaxed geometry

Replica exchange MD simulations of two-dimensional water in graphene nanocapillaries: rhombic versus square structures, proton ordering, and phase transitions

2019 ◽  
Vol 21 (32) ◽  
pp. 17640-17654
Author(s):  
Shujuan Li ◽  
Burkhard Schmidt
Keyword(s):  
Phase Transitions ◽  
Minimum Energy ◽  
Md Simulations ◽  
Replica Exchange ◽  
Graphene Sheets ◽  
Two Dimensional ◽  
Proton Ordering

Minimum energy structures of quasi-two dimensional ice confined between graphene sheets.

Conformation and electronic structure of Carbidopa. A QM/MD study

2016 ◽  
Vol 15 (01) ◽  
pp. 1650002
Author(s):  
Ghader M. Sukker ◽  
Nuha Wazzan ◽  
Ashour Ahmed ◽  
Rifaat Hilal
Keyword(s):  
Density Functional ◽  
Minimum Energy ◽  
Geometry Optimization ◽  
Md Simulations ◽  
Energy Structure ◽  
Functional Theory ◽  
Conformational Preferences ◽  
The Density Functional Theory ◽  
Quantum Chemical Topology ◽  
Bonding Characteristics

Carbidopa (CD) is a drug used in combination with L-dopa (LD) in treatment of Parkinson’s disease (PD). CD is an inhibitor for enzyme decarboxylase, yet its mode of action is not entirely known although it is believed to involve enzyme shape recognition. The present work attempts to investigate the conformational preferences of CD. Tight geometry optimization at the density functional theory (DFT)/B3LYP/6-311[Formula: see text]G** level of theory has been carried out. The shallow nature of the potential energy surface (PES) and the presence of several local minima within a small energy range necessitate the launching of DFT-based molecular dynamics (MD) simulations. Two MD experiments were submitted for 35,000 points each. The complete trajectory in time domain of 10.5 ps is analyzed and discussed. The global minimum energy structure of CD is localized and identified by subsequent frequency calculations. The quantum theory of atom in molecules (QTAIMs) is used to extract and compare the quantum chemical topology features of the electron density distribution in CD and LD. Bonding characteristics are analyzed and discussed within the natural bond orbital (NBO) framework.

scholarly journals Discovering minimum energy pathways via distortion symmetry groups

2018 ◽  
Vol 98 (8) ◽  
Author(s):  
Jason M. Munro ◽  
Hirofumi Akamatsu ◽  
Haricharan Padmanabhan ◽  
Vincent S. Liu ◽  
Yin Shi ◽  
...  
Keyword(s):  
Minimum Energy ◽  
Symmetry Groups ◽  
Energy Pathways

Study on Nanoimprint Lithography of the Polymer Chains (CH2)n With Anti-Adhesion Layer on Stamp by Molecular Dynamics Method

2008 ◽  
Author(s):  
Quang-Cherng Hsu ◽  
Chien-Liang Lin ◽  
Te-Hua Fang
Keyword(s):  
Molecular Dynamics ◽  
Polymer Material ◽  
Nanoimprint Lithography ◽  
Minimum Energy ◽  
Md Simulations ◽  
Atomic Scale ◽  
Polymer Materials ◽  
Energy Status ◽  
Adhesion Layer ◽  
System Energy

This paper aims at the study on nanoimprint lithography (NIL) of the polymer material in (CH2)n Chains. The simulation codes were built based on molecular dynamics (MD) method for observing material deformation behaviors in atomic scale. The deformation mechanism of NIL of polymer material (CH2)n pressed by silicon stamp was first studied, by which the effects of critical punch tip width, imprint depth, temperature, and adhesion effect were studied. Next, the nanoimprint processes with stamp tips covered by anti-adhesion material, which is a self-assembled monolayer (SAM), were studied to compare to those processes without having anti-adhesion layer. When deforming polymer material at or above room temperature, adhesion problems occur between stamp and polymer. Polymer materials adhere to stamp more severe than they adhere to each others because potential energies between long chains of polymers are smaller than those between polymer and stamp. From the relation between system energy and stamp translation based on the MD simulations, the system energy increases when stamp moves gradually. When unloading, the system energy will return to its minimum energy status and remains stable. However, when punch leaves polymer materials, energy fluctuation occurs due to some polymer materials adhere to the stamp. Finally, the analysis of stamp with and without SAM based on the MD method was conducted and discussed.

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