Global minima of protonated water clusters

2000 ◽  
Vol 324 (4) ◽  
pp. 279-288 ◽  
Author(s):  
Matthew P. Hodges ◽  
David J. Wales
Keyword(s):  
Water Clusters ◽  
Global Minima

scholarly journals Resolving the HONO formation mechanism in the ionosphere via ab initio molecular dynamic simulations

2016 ◽  
Vol 113 (17) ◽  
pp. 4629-4633 ◽  
Author(s):  
Rongxing He ◽  
Lei Li ◽  
Jie Zhong ◽  
Chongqin Zhu ◽  
Joseph S. Francisco ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Nitrous Acid ◽  
Water Clusters ◽  
Ab Initio Molecular Dynamics ◽  
Molecular Dynamic Simulations ◽  
Global Minima ◽  
Dynamic Simulations ◽  
Transition State Search ◽  
A Chain

Solar emission produces copious nitrosonium ions (NO+) in the D layer of the ionosphere, 60 to 90 km above the Earth’s surface. NO+ is believed to transfer its charge to water clusters in that region, leading to the formation of gaseous nitrous acid (HONO) and protonated water cluster. The dynamics of this reaction at the ionospheric temperature (200–220 K) and the associated mechanistic details are largely unknown. Using ab initio molecular dynamics (AIMD) simulations and transition-state search, key structures of the water hydrates—tetrahydrate NO+(H2O)4 and pentahydrate NO+(H2O)5—are identified and shown to be responsible for HONO formation in the ionosphere. The critical tetrahydrate NO+(H2O)4 exhibits a chain-like structure through which all of the lowest-energy isomers must go. However, most lowest-energy isomers of pentahydrate NO+(H2O)5 can be converted to the HONO-containing product, encountering very low barriers, via a chain-like or a three-armed, star-like structure. Although these structures are not the global minima, at 220 K, most lowest-energy NO+(H2O)4 and NO+(H2O)5 isomers tend to channel through these highly populated isomers toward HONO formation.

Global minima for water clusters (H2O)n, n⩽21, described by a five-site empirical potential

2005 ◽  
Vol 415 (4-6) ◽  
pp. 302-307 ◽  
Author(s):  
Tim James ◽  
David J. Wales ◽  
Javier Hernández-Rojas
Keyword(s):  
Water Clusters ◽  
Global Minima ◽  
Empirical Potential

Global Minima of Protonated Water Clusters (H2O)20H+ Revisited

2012 ◽  
Vol 116 (44) ◽  
pp. 10826-10835 ◽  
Author(s):  
P. Parkkinen ◽  
S. Riikonen ◽  
L. Halonen
Keyword(s):  
Water Clusters ◽  
Global Minima

scholarly journals Isomers and energy landscapes of micro-hydrated sulfite and chlorate clusters

2018 ◽  
Vol 376 (2115) ◽  
pp. 20170154 ◽  
Author(s):  
John C. Hey ◽  
Emily J. Doyle ◽  
Yuting Chen ◽  
Roy L. Johnston
Keyword(s):  
Global Minimum ◽  
Water Clusters ◽  
Structure Optimization ◽  
Theoretical Chemistry ◽  
Hydroxyl Groups ◽  
Energy Landscapes ◽  
Global Minima ◽  
Theme Issue ◽  
Empirical Potential ◽  
Basin Hopping

We present putative global minima for the micro-hydrated sulfite SO 3 2− (H 2 O) N and chlorate ClO 3 − (H 2 O) N systems in the range 3≤ N ≤15 found using basin-hopping global structure optimization with an empirical potential. We present a structural analysis of the hydration of a large number of minimized structures for hydrated sulfite and chlorate clusters in the range 3≤ N ≤50. We show that sulfite is a significantly stronger net acceptor of hydrogen bonding within water clusters than chlorate, completely suppressing the appearance of hydroxyl groups pointing out from the cluster surface (dangling OH bonds), in low-energy clusters. We also present a qualitative analysis of a highly explored energy landscape in the region of the global minimum of the eight water hydrated sulfite and chlorate systems. This article is part of the theme issue ‘Modern theoretical chemistry’.

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