Study of Hydrodesulfurization by Transition Metal Sulfides by Means of the Laplacian of the Electronic Charge Density

Theoretical Electron Density Distributions for Fe- and Cu-Sulfide Earth Materials: A Connection between Bond Length, Bond Critical Point Properties, Local Energy Densities, and Bonded Interactions

“…Further, the bond lengths for the two disulfide polymorphs fall off the dashed curve in Figure a with their ρ( r c ) values ∼0.15 e/Å 3 larger than those calculated for the sulfides with 6-coordinate high-spin nominally divalent Fe. The bcp properties calculated for pyrite are in exact agreement with those calculated earlier by Aray et al , …”

Theoretical Electron Density Distributions for Fe- and Cu-Sulfide Earth Materials: A Connection between Bond Length, Bond Critical Point Properties, Local Energy Densities, and Bonded Interactions

“…Further, the bond lengths for the two disulfide polymorphs fall off the dashed curve in Figure a with their ρ( r c ) values ∼0.15 e/Å 3 larger than those calculated for the sulfides with 6-coordinate high-spin nominally divalent Fe. The bcp properties calculated for pyrite are in exact agreement with those calculated earlier by Aray et al , …”

Adsorption of Thiophene on the RuS2(100) and (111) Surfaces: A Laplacian of the Electronic Charge Density Study

“…The corresponding atomic graphs, AG, are shown in Figure . Similar to the bulk case, the top Ru atoms show a cubelike AG with a set of indices equal to (8, 12, 6), in which eight vertexes are linked by 12 edges and there are six faces joining those vertexes. Each face is defined by four edges.…”

“…We have located all of the critical points (CPs) on the valence shell charge concentrations, VSCC, of the outermost Ru and S atoms for the studied surfaces. The metal atoms, as in free and bulk atoms, exhibited only four shells of charge concentrations, so that 4s4p4d electrons form the VSCC. The number, positions, and L ( r ) values at the calculated CPs for the Ru atoms are listed in Table .…”

“…b The position of the CPs are given with respect to the layer containing the topmost Ru nucleus. c Ref .…”

Correlation between Electronic Properties and Hydrodesulfurization Activity of 4d-Transition-Metal Sulfides

“…Thus, TMSs with intermediate cohesive energy per metal−sulfur bond have the highest HDS activities, confirming that the cohesive energy is the most adequate parameter able to quantitatively render the electronic trend in TMSs. , Through the use of this redefinition of the metal−sulfur bond strength, MnS is not present anymore at the optimum range of strength . Specially, a critical-point analysis of the charge density has been made . This robust topological approach furnishes a simple correlation between the sulfur−metal bond energy and the Laplacian of the charge density and distinguishes clearly between ionic and covalent character of the bond.…”

Theoretical Electron Density Distributions for Fe- and Cu-Sulfide Earth Materials: A Connection between Bond Length, Bond Critical Point Properties, Local Energy Densities, and Bonded Interactions

“…Further, the bond lengths for the two disulfide polymorphs fall off the dashed curve in Figure a with their ρ( r c ) values ∼0.15 e/Å 3 larger than those calculated for the sulfides with 6-coordinate high-spin nominally divalent Fe. The bcp properties calculated for pyrite are in exact agreement with those calculated earlier by Aray et al , …”

Adsorption of Thiophene on the RuS2(100) and (111) Surfaces: A Laplacian of the Electronic Charge Density Study

“…The corresponding atomic graphs, AG, are shown in Figure . Similar to the bulk case, the top Ru atoms show a cubelike AG with a set of indices equal to (8, 12, 6), in which eight vertexes are linked by 12 edges and there are six faces joining those vertexes. Each face is defined by four edges.…”

“…We have located all of the critical points (CPs) on the valence shell charge concentrations, VSCC, of the outermost Ru and S atoms for the studied surfaces. The metal atoms, as in free and bulk atoms, exhibited only four shells of charge concentrations, so that 4s4p4d electrons form the VSCC. The number, positions, and L ( r ) values at the calculated CPs for the Ru atoms are listed in Table .…”

“…b The position of the CPs are given with respect to the layer containing the topmost Ru nucleus. c Ref .…”

Correlation between Electronic Properties and Hydrodesulfurization Activity of 4d-Transition-Metal Sulfides

“…Thus, TMSs with intermediate cohesive energy per metal−sulfur bond have the highest HDS activities, confirming that the cohesive energy is the most adequate parameter able to quantitatively render the electronic trend in TMSs. , Through the use of this redefinition of the metal−sulfur bond strength, MnS is not present anymore at the optimum range of strength . Specially, a critical-point analysis of the charge density has been made . This robust topological approach furnishes a simple correlation between the sulfur−metal bond energy and the Laplacian of the charge density and distinguishes clearly between ionic and covalent character of the bond.…”

Theoretical Electron Density Distributions for Fe- and Cu-Sulfide Earth Materials: A Connection between Bond Length, Bond Critical Point Properties, Local Energy Densities, and Bonded Interactions

“…Further, the bond lengths for the two disulfide polymorphs fall off the dashed curve in Figure a with their ρ( r c ) values ∼0.15 e/Å 3 larger than those calculated for the sulfides with 6-coordinate high-spin nominally divalent Fe. The bcp properties calculated for pyrite are in exact agreement with those calculated earlier by Aray et al , …”

Adsorption of Thiophene on the RuS2(100) and (111) Surfaces: A Laplacian of the Electronic Charge Density Study

“…The corresponding atomic graphs, AG, are shown in Figure . Similar to the bulk case, the top Ru atoms show a cubelike AG with a set of indices equal to (8, 12, 6), in which eight vertexes are linked by 12 edges and there are six faces joining those vertexes. Each face is defined by four edges.…”

“…We have located all of the critical points (CPs) on the valence shell charge concentrations, VSCC, of the outermost Ru and S atoms for the studied surfaces. The metal atoms, as in free and bulk atoms, exhibited only four shells of charge concentrations, so that 4s4p4d electrons form the VSCC. The number, positions, and L ( r ) values at the calculated CPs for the Ru atoms are listed in Table .…”

“…b The position of the CPs are given with respect to the layer containing the topmost Ru nucleus. c Ref .…”

Correlation between Electronic Properties and Hydrodesulfurization Activity of 4d-Transition-Metal Sulfides

“…Thus, TMSs with intermediate cohesive energy per metal−sulfur bond have the highest HDS activities, confirming that the cohesive energy is the most adequate parameter able to quantitatively render the electronic trend in TMSs. , Through the use of this redefinition of the metal−sulfur bond strength, MnS is not present anymore at the optimum range of strength . Specially, a critical-point analysis of the charge density has been made . This robust topological approach furnishes a simple correlation between the sulfur−metal bond energy and the Laplacian of the charge density and distinguishes clearly between ionic and covalent character of the bond.…”