PENALTYPOT

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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:

,

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

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

Related tags and articles

MDALGO, ICONST