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:

x_1 x_2 ... x_m  h w

,

where $x_1$ to $x_m$ stand for the position in the space of active coordinates, and $h$ and $w$ are the height and width of the Gaussian, respectively. Note that both positive and negative values are allowed for the parameter $h$ .

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

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