Dear Users, The constraint subroutine takes the form: subroutine constr( cell, na, isa, amass, xa, stress, fa, ntcon ). It doesn't contain information about energy.
Now I am using a harmonic potential with a stiff spring to constrain a pair of atoms separated by a distance of r0. I should be able to pass the constraint harmonic energy V=1/2 * k * (rij - r0)^2 to the subroutine to be added to the total energy i.e., E + 1/2 * k * (rij - r0)^2 will be the total energy. Which routines should I modify to allow the total energy to account for the constraint energy?
-- SIESTA is supported by the Spanish Research Agency (AEI) and by the European H2020 MaX Centre of Excellence (http://www.max-centre.eu/)
