Ab Initio Simulation of Changes in Geometry, Electronic Structure, and Gibbs Free Energy Caused by Dehydration of Hydrotalcites Containing Cl−and CO32−Counteranions

2011 ◽  
Vol 115 (13) ◽  
pp. 3531-3537 ◽  
Author(s):  
Deyse G. Costa ◽  
Alexandre B. Rocha ◽  
Wladmir F. Souza ◽  
Sandra Shirley X. Chiaro ◽  
Alexandre A. Leitão
Keyword(s):  
Free Energy ◽  
Electronic Structure ◽  
Ab Initio ◽  
Gibbs Free Energy ◽  
Ab Initio Simulation

scholarly journals Effective n-type F-doped MoSe2 monolayers

RSC Advances ◽  
2017 ◽  
Vol 7 (43) ◽  
pp. 26673-26679 ◽  
Author(s):  
Xu Zhao ◽  
Xiaonan Zhang ◽  
Tianxing Wang ◽  
Shuyi Wei ◽  
Lin Yang
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Structure Formation ◽  
First Principles ◽  
Formation Energy ◽  
Ab Initio Simulation ◽  
Transition Level ◽  
Simulation Package ◽  
First Principles Method

Using a first-principles method, based on the Vienna Ab-initio Simulation Package (VASP), we have studied the electronic structure, formation energy and transition level of a MoSe2 monolayer doped with V and VII atoms.

scholarly journals Ab initio simulation of a 57-residue protein in explicit solvent reproduces the native conformation in the lowest free-energy cluster

2010 ◽  
Vol 20 (1) ◽  
pp. 187-196 ◽  
Author(s):  
Jinzen Ikebe ◽  
Daron M. Standley ◽  
Haruki Nakamura ◽  
Junichi Higo
Keyword(s):  
Free Energy ◽  
Ab Initio ◽  
Native Conformation ◽  
Ab Initio Simulation ◽  
Explicit Solvent ◽  
Energy Cluster

Thermodynamic Analysis of a Brown Glass Containing Fe, C and S

2012 ◽  
Vol 591-593 ◽  
pp. 973-976
Author(s):  
Chang Sheng Hu ◽  
Jun Zhang ◽  
Hong Fei Yan ◽  
Jin Xin He
Keyword(s):  
Free Energy ◽  
Ab Initio ◽  
Gibbs Free Energy ◽  
Chemical Stability ◽  
Ground State ◽  
Heat Stability ◽  
High Energy ◽  
Ab Initio Methods ◽  
Ab Initio Method ◽  
Ring Molecules

The ground state geometrical of cyclic sulfur molecules S8 has been studied with RHF/6-311G* of ab initio methods. Gibbs free energy of CO, SO2, S8 and CO2 from 300 to 1673K has been calculated using ab initio method. Besides, the reaction free enthalpies were calculated. The results show that resultants of reaction of CO and SO2 are S8 and CO2 below 1451K and the reaction is spontaneous.Fe2O3 in glass can is reduced into FeO whose redox number is negative. The Gibbs free energy of FeO is smaller than that of FeS while chemical stability of FeO is higher than that of FeS. Structures of cycle sulfur are versatile. Bond energy of S8, S12 and S18 is broken, which need high energy. When small sulfur ring molecules be formed, the chemical and heat stability of S8 are improved.

scholarly journals Large-scale QM/MM free energy simulations of enzyme catalysis reveal the influence of charge transfer

2018 ◽  
Author(s):  
Heather Kulik
Keyword(s):  
Free Energy ◽  
Electronic Structure ◽  
Charge Transfer ◽  
Ab Initio ◽  
Density Functional ◽  
Large Scale ◽  
Active Site Residues ◽  
Functional Theory ◽  
Energy Simulations ◽  
Electrostatic Embedding

Hybrid quantum mechanical-molecular mechanical (QM/MM) simulations provide key insights into enzyme structure–function relationships. Numerous studies have demonstrated that large QM regions are needed to systematically converge ground state, zero temperature properties with electrostatic embedding QM/MM. However, it is not well known if <i>ab initio </i>QM/MM free energy simulations have this same dependence, in part due to the hundreds of thousands of energy evaluations required for free energy estimations that in turn limit QM region size. Here, we leverage recent advances in electronic structure efficiency and accuracy to carry out range-separated hybrid density functional theory free energy simulations in a representative methyltransferase. By studying 200 ps of <i>ab initio </i>QM/MM dynamics for each of five QM regions from minimal (64 atoms) to one-sixth of the protein (544 atoms), we identify critical differences between large and small QM region QM/MM in charge transfer between substrates and active site residues as well as in geometric structure and dynamics that coincide with differences in predicted free energy barriers. Distinct geometric and electronic structure features in the largest QM region indicate that important aspects of enzymatic rate enhancement in methyltransferases are identified with large-scale electronic structure.<br>

Ab initio simulation of the electronic structure of δ-Ta2O5 with oxygen vacancy and comparison with experiment

2011 ◽  
Vol 112 (6) ◽  
pp. 1035-1041 ◽  
Author(s):  
M. V. Ivanov ◽  
T. V. Perevalov ◽  
V. Sh. Aliev ◽  
V. A. Gritsenko ◽  
V. V. Kaichev
Keyword(s):  
Electronic Structure ◽  
Oxygen Vacancy ◽  
Ab Initio ◽  
Ab Initio Simulation ◽  
Comparison With Experiment
Sign in / Sign up

Export Citation Format

Share Document