Molecular dynamics (MD) simulations were conducted using NAMD v 2.10 and employing CHARMM27 force field39, extended with INTERFACE FF v1.5 (INTFF) parameters for mica40, and the TIP3P water model41. A single layer of mica, spanning 52 × 54 Å, was constructed using the INTFF provided structures. Two monomers of Aβ(14-23) were then placed at Center-of-Mass (COM) distance of 2 nm above the mica surface. The initial monomer structure (Figure S9) was adopted from ref. 23. To mimic the experimental design, a Cys residue was added to the N-terminus of the peptide. The index of this Cys residue was set to 0 to keep the context of the other residues as the actual Aβ42 protein. Because we do not know the behavior of the cations on the mica surface, we performed simulations of two different mica surfaces: one, which allowed the K cations to freely move during the simulation, called Mica1, and another system where the K cations were restrained to their crystal positions as obtained from42, called Mica2. Both systems were then solvated with TIP3P water molecules. Na+ and Cl− ions were then added to neutralize the charges and maintain an ionic concentration of 150 mM. Other details of the simulations setup were adopted from our previous work23. 20 ns NVT simulation was then performed. After which 520 ns NPT production simulation, at 1 bar and 300 K, were carried out for each system using Crane at the Holland Computing Center (HCC) and Comet at San Diego Supercomputer Center (SDSC).