[gmx-users] 2D umbrella sampling simulation

[Christopher Neale]

Your restraint involving group C should use pull_group2, etc, not another copy of pull_group1. Other than that,
it looks like a valid approach.

Chris.

-- original message --

    I am going to perform the two-dimensional umbrella sampling using a pair of distances (the distance btw atoms A and B, C and B) in the restraints. Could someone please tell whether I can use the current pull code as follows?
---------------------------------------------
; Pull code
pull            = umbrella
pull_geometry   = distance
pull_dim        = Y Y Y
pull_start      = no
pull_ngroups    = 2
pull_group0     = B
pull_group1     = A ;restraint of distance btw A and B
pull_init1      = 2.7 ;equilibrium distance of A-B
pull_rate1      = 0.0
pull_k1         = 2000      ; kJ mol^-1 nm^-2

pull_group1     = C ;restraint of distance btw C and B
pull_init1      = 3.7 ;equilibrium distance of C-B
pull_rate1      = 0.0
pull_k1         = 2500      ; kJ mol^-1 nm^-2

pull_nstxout    = 1000      ; every 2 ps
pull_nstfout    = 1000      ; every 2 ps
------------------------------------------------- 

Many thanks.