IRCCAR
The IRCCAR file defines a discretized transformation path. Usually this is taken from an intrinsic reaction coordinate (IRC) - using IBRION=40, projected onto a small set of internal coordinates. It is required to define the path-based coordinates IS and IZ in ICONST [1].
However, this path is followed during a biased molecular dynamics (MD) simulation, similar to the Blue moon ensemble method, metadynamics, and other advanced MD aproaches [2]. The structure of the file is:
M chi_1(1) chi_2(1) ... chi(r)(1) chi_1(2) chi_2(2) ... chi(r)(2) ... chi_1(M) chi_2(M) ... chi(r)(M)
where M is the number of points in the file and chi_j(i) is [math]\displaystyle{ \tilde{\chi}_k(i) }[/math], the discretized transformation path in terms of internal coordinates, taking values between 0 and 1.
| Mind: Contact [Tomáš Bučko] for necessary Python scripts to prepare this file. |