1. 1 2 QCDFT Method ? Cauchy-Born rule with EAM cal.
Gang Lu, Department of Physics & Astronomy, California State University Northridge, CA
Three levels of simulations running concurrently: DFT (1)+EAM(2)+FEM(3)
Quasicontinuum (QC): Treat non-local QC atoms with coupled DFT/EAM approach; local QC with EAM-based Cauchy-Born rule 1 2 ?
We recently developed a method called QCDFT that can resolve these two problems. In QCDFT method, we treat non-local QC atoms with coupled DFT and EAM multiscale approach. The important quantum mechanical processes, such as chemical reactions, bond-breakings, etc. are all treated explicitly with DFT calculations in region 1 of yellow atoms. Region 2 is treated with classical EAM calculations and the region 2 extends to the entire non-local QC region. For the local QC region, we’ll use the Cauchy-Born rule with the same EAM potential. Our next speaker will talk about local QC so I’ll skip it. But the local calculations with Cauchy-Born rule essentially solve the 1st problem I was talking about. The question now is how to couple 1 and 2 without cutting bonds.
Cauchy-Born rule with EAM cal.
Important quantum mechanical processes treated with DFT in region 1
Region 2 treated by EAM; extends to the entire non-local QC region; local QC by Cauchy-Born rule with EAM cal.