Theoretical Investigation of CO Interaction with Copper Sites in Zeolites:  Periodic DFT and Hybrid Quantum Mechanical/Interatomic Potential Function Study

2005 ◽  
Vol 109 (19) ◽  
pp. 9631-9638 ◽  
Author(s):  
Ota Bludský ◽  
Martin Silhan ◽  
Petr Nachtigall ◽  
T. Bucko ◽  
L. Benco ◽  
...  
Keyword(s):  
Potential Function ◽  
Theoretical Investigation ◽  
Interatomic Potential ◽  
Quantum Mechanical ◽  
Function Study ◽  
Copper Sites ◽  
Periodic Dft

Coordination and siting of Cu+ ions in ZSM-5: A combined quantum mechanics/interatomic potential function study

1999 ◽  
Vol 1 (8) ◽  
pp. 2019-2026 ◽  
Author(s):  
Dana Nachtigallová ◽  
Petr Nachtigall ◽  
Marek Sierka ◽  
Joachim Sauer
Keyword(s):  
Quantum Mechanics ◽  
Potential Function ◽  
Interatomic Potential ◽  
Function Study ◽  
Cu Ions

scholarly journals “Inverted” CO molecules on NaCl(100): a quantum mechanical study

2021 ◽  
Author(s):  
Shreya Sinha ◽  
Peter Saalfrank
Keyword(s):  
Vibrational Excitation ◽  
Quantum Mechanical ◽  
Mechanical Description ◽  
Quantum Mechanical Description ◽  
Mechanical Study ◽  
Quantum Mechanical Study ◽  
Periodic Dft

Inverted (“O-down”) CO adsorbates on NaCl(100), recently observed experimentally after IR vibrational excitation (Lau et al., Science, 2020, 367, 175–178), are characterized using periodic DFT and a quantum mechanical description of vibrations.

scholarly journals Global Diastereoconvergence in the Ireland–Claisen Rearrangement of Isomeric Enolates: Synthesis of Tetrasubstituted -Amino Acids

2020 ◽  
Author(s):  
Tyler J. Fulton ◽  
Alexander Cusumano ◽  
Eric J. Alexy ◽  
Yun Emily Du ◽  
Haiming Zhang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Theoretical Investigation ◽  
Claisen Rearrangement ◽  
State Of The Art ◽  
Coupled Cluster ◽  
Quantum Mechanical ◽  
Density Func Tional Theory ◽  
Coupled Cluster Theory ◽  
Enol Ethers ◽  
Allyl Esters

<div><div><div><p>A dual experimental/theoretical investigation of the Ireland–Claisen rearrangement of tetrasubstituted a-phthalimido ester enolates to afford a-tetrasubstituted, b-trisubstituted a-amino acids (generally >20:1 dr) is described. For trans allylic olefins, the Z and E-enol ethers proceed through chair and boat transition states, respectively. For cis allylic olefins, the trend is reversed. As a result, the diastereochemical outcome of the reaction is preserved regardless of the geometry of the enolate or the accompanying allylic olefin. We term this unique convergence of all possible olefin isomers as global diastereoconvergence. This reaction manifold circumvents limitations in present-day technologies for the stereoselective enolization of a,a-disubstituted allyl esters. Density func- tional theory paired with state-of-the-art local coupled-cluster theory (DLPNO-CCSD(T)) was employed for the accurate determina- tion of quantum mechanical energies.</p></div></div></div>

scholarly journals Molecular Dynamics Study on Lubrication Mechanism in Crystalline Structure between Copper and Sulfur

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Ken-ichi Saitoh ◽  
Tomohiro Sato ◽  
Masanori Takuma ◽  
Yoshimasa Takahashi ◽  
Ryuketsu Chin
Keyword(s):  
Molecular Dynamics ◽  
Shear Stress ◽  
Potential Function ◽  
Crystalline Structure ◽  
Interatomic Potential ◽  
Hexagonal Phase ◽  
Interatomic Interaction ◽  
Md Simulations ◽  
Shear Loading ◽  
Atomistic Modeling

To clarify the nanosized mechanism of good lubrication in copper disulfide (Cu2S) crystal which is used as a sliding material, atomistic modeling of Cu2S is conducted and molecular dynamics (MD) simulations are performed in this paper. The interatomic interaction between atoms and crystalline structure in the phase of hexagonal crystal of Cu2S are carefully estimated by first-principle calculations. Then, approximating these interactions, we originally construct a conventional interatomic potential function of Cu2S crystal in its hexagonal phase. By using this potential function, we perform MD simulation of Cu2S crystal which is subjected to shear loading parallel to the basal plane. We compare results obtained by different conditions of sliding directions. Unlike ordinary hexagonal metallic crystals, it is found that the easy-glide direction does not always show small shear stress for Cu2S crystal. Besides, it is found that shearing velocity affects largely the magnitude of averaged shear stress. Generally speaking, higher velocity results in higher resistance against shear deformation. As a result, it is understood that Cu2S crystal exhibits somewhat liquid-like (amorphous) behavior in sliding condition and shear resistance increases with increase of sliding speed.

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