anchor.diff:  
     call colloid_lj% init(epsilon(1:2,:), sigma(1:2,:), sigma_cut(1:2,:))
   
  -  epsilon(1,1) = 1.d0
  -  epsilon(1,2) = 1.d0
  -  epsilon(2,1) = 1.d0
  -  epsilon(2,2) = 1.d0
  +  epsilon = 1.d0
     sigma(1,:) = [sigma_C, sigma_N]
     sigma(2,:) = [sigma_C, sigma_N]
  -  sigma_cut = sigma*2**(1.d0/6.d0)
  -
  -  call walls_colloid_lj% init(epsilon(1:2,:), sigma(1:2,:), sigma_cut(1:2,:))
  +  sigma_cut = sigma*3**(1.d0/6.d0)
  +  shift = maxval(colloid_lj% cut) +0.25
  +  call walls_colloid_lj% init(epsilon(1:2,:), sigma(1:2,:), sigma_cut(1:2,:), shift)
   
     mass(1) = rho * sigma_C**3 * 4 * 3.14159265/3
     mass(2) = rho * sigma_N**3 * 4 * 3.14159265/3
  
positive.code: 
    open(17,file ='dimerdata_FullExp_1.txt')
    open(19,file ='dimerdata_vx_flow_wall.txt')  
    open(18,file ='local_conc.txt')
    colloids% species(1) = 1
    colloids% species(2) = 2
    colloids% vel = 0
  
negative.code:      if (i .gt. 2000) then
          fixed = .false.
       end if
       
    end do setup
  
    call thermo_data%append(hfile, temperature, e1+e2+e_wall, kin_e, e1+e2+e_wall+kin_e, add=.false., force=.true.)
  