PENALTYPOT
File that defines the bias potential for a biased molecular-dynamics run.
At the beginning of each metadynamics simulation, VASP attempts to read the file PENALTYPOT containing the bias potential acting on the geometric parameters with STATUS=5 defined in the ICONST file. In analogy to the time-dependent bias potential generated in metadynamics, the bias potential is defined as a superposition of Gaussian hills. Each line in the PENALTYPOT file represents one (multidimensional) Gaussian:
- [math]\displaystyle{ x_1 x_2 ... x_m h w }[/math],
where [math]\displaystyle{ x_1 }[/math] to [math]\displaystyle{ x_m }[/math] stand for the position in the space of active coordinates, and [math]\displaystyle{ h }[/math] and [math]\displaystyle{ w }[/math] are the height and width of the Gaussian, respectively. Note that both positive and negative values are allowed for the parameter [math]\displaystyle{ h }[/math].
For example, if two active coordinates with STATUS=5 are defined in the ICONST file:
R 1 5 5 R 1 6 5
then each line in the PENALTYPOT must contain four items. The bias potential is defined in the following lines:
1.6 0.8 1.0 0.2 1.6 1.0 1.0 0.2 1.6 1.2 1.0 0.2 1.6 1.4 1.0 0.2 1.6 1.6 1.0 0.2 1.6 1.8 1.0 0.2 1.6 2.0 1.0 0.2