[gmx-users] Hessian matrix

[Nguyen Hoang Phuong]

Dear All,

in gromacs, the matrix elements of the Hessian matrix are numerically
calculated by using the finite differentiation method which I think like
this (please correct me if it is wrong)

d^2f/dx^2 = {f(x+dx) - 2f(x) + f(x-dx)}/(2*dx)

I would like to ask if some of you know what is value of the interval dx?

Thanks in advance.

Phuong