Computational modeling of the impact of functional groups on asphaltene aggregates via Random Phase Approximation
Presentation Type
Poster
Faculty Advisor
Hendrik Eshuis
Access Type
Event
Start Date
26-4-2023 9:45 AM
End Date
26-4-2023 10:44 AM
Description
Van der Waals interactions play a crucial role in hydrocarbon chemistry. Computing van der Waals interactions becomes problematic when implemented in computational chemistry. The use of efficient density functional methods fail to describe weak interactions and more accurate wave-function based methods are too computationally expensive to be applied to large systems. The use of random phase approximation (RPA) is what will be proposed to include van der Waals interactions in hydrocarbon reaction mechanisms. A unique property relating to asphaltenes is their capability to stack on each other. Aromatic rings found in these structures introduce pi-stacking into the system, which contributes greatly to the stacking effect. The type and number of functional groups attached to the hydrocarbons may affect the binding energy of the system as well. With the use of RPA, we can quantitate the effectiveness of the cooperative binding in asphaltenes and gain a deeper insight on these systems. Additionally, high-level theory (DLPNO-CCSD(T)) can be used to obtain very accurate data for smaller systems and tight-binding methods to model very large clusters. All calculations will be done using TURBOMOLE with a CREST extension. BASH scripts were written to streamline the large number of calculations and analyze the data. The modeling of molecules will be done using Avogadro. Tight-binding in conjunction with metadynamics was employed to sample the conformational space.
Computational modeling of the impact of functional groups on asphaltene aggregates via Random Phase Approximation
Van der Waals interactions play a crucial role in hydrocarbon chemistry. Computing van der Waals interactions becomes problematic when implemented in computational chemistry. The use of efficient density functional methods fail to describe weak interactions and more accurate wave-function based methods are too computationally expensive to be applied to large systems. The use of random phase approximation (RPA) is what will be proposed to include van der Waals interactions in hydrocarbon reaction mechanisms. A unique property relating to asphaltenes is their capability to stack on each other. Aromatic rings found in these structures introduce pi-stacking into the system, which contributes greatly to the stacking effect. The type and number of functional groups attached to the hydrocarbons may affect the binding energy of the system as well. With the use of RPA, we can quantitate the effectiveness of the cooperative binding in asphaltenes and gain a deeper insight on these systems. Additionally, high-level theory (DLPNO-CCSD(T)) can be used to obtain very accurate data for smaller systems and tight-binding methods to model very large clusters. All calculations will be done using TURBOMOLE with a CREST extension. BASH scripts were written to streamline the large number of calculations and analyze the data. The modeling of molecules will be done using Avogadro. Tight-binding in conjunction with metadynamics was employed to sample the conformational space.