Slides

QM/MM: CPMD/GROMOS
• Hamiltonian formula4on from which the addi4onal external
electrosta4c poten4al to be included in the Kohn-­‐Sham Hamiltonian
and the one ac4ng onto the MM atoms as results of the QM charge
distribu4on can be obtained consistently.
• Electrosta4c part is split into short-­‐range and long-­‐range contribu4ons
E es
QM −MM
QM −MM
= E es− sr
∑
QM −MM
+ E es−lr
= q I
n(r)υ I
eff
I ∈NN
∫
(
QM − MM
r − R I )dr + E es−lr
• Short-­‐range:
• only stemming from „nearest-­‐neighbour“ (NN) MM atoms located
within a certain cutoff range around QM atoms.
• Evaluated exactly by summing all grid-­‐point/MM atom
contribu4ons in the NN class explicitly („modified Coulomb
interac4on“).
A. Laio, J. VandeVondele, U. Röthlisberger J. Chem. Phys. 2002, 116, 6941.