This is a simple tool to predict energies and forces of a single configuration, given an existing HDNNP parameterization.


The HDNNP setup, symmetry function scaling data and weight parameters are required in the usual files:

  • input.data

  • input.nn

  • scaling.data

  • weights.???.data


nnp-predict <info>
            <info> ... Write structure information for debugging to "structure.out" (0/1)

The tool will output the resulting potential energy and atomic forces on the screen and in files (see sections below). Enabling the additional debugging output to is usually not necessary. The file “structure.out” contains basically the entire content of the Structure and Atom instances, i.e. the full neighbor lists and symmetry function derivatives of all atoms.


Depending on the configuration the “structure.out” debugging file can be huge.

Sample screen output:

*** PREDICTION ****************************************************************

Reading structure file...
Structure contains 144 atoms (2 elements).
Calculating NNP prediction...

NNP energy:  -5.73656032E+02

NNP forces:
         1  S  -1.40007861E-01   2.74032613E-02  -5.96150479E-03
         2  S   1.39972905E-01   2.73894285E-02   5.93808974E-03
         3  S   1.39988541E-01  -2.73969011E-02   6.02337848E-03
         4  S  -1.39985315E-01  -2.73976741E-02  -6.01454763E-03
         5  S  -1.34194641E-01  -3.09539812E-02   3.93006430E-02
       140 Cu   4.22986438E-02  -1.77295621E-02   3.63706424E-02
       141 Cu  -3.57169850E-02   7.57362417E-02   1.68472680E-03
       142 Cu   3.57606444E-02   7.57328191E-02  -1.65808098E-03
       143 Cu   3.57294618E-02  -7.57352222E-02  -1.67173728E-03
       144 Cu  -3.57158597E-02  -7.57244307E-02   1.68265914E-03
Writing output files...
 - energy.out
 - nnatoms.out
 - nnforces.out
Writing structure with NNP prediction to "output.data".

File output:

  • energy.out: Contains the potential energy predicted by the NNP.

  • nnforces.out: Contains the atomic forces predicted by the NNP.

  • nnatoms.out: Contains the atomic energy contributions to the total potential energy.

  • output.data: Contains the configuration just like in the input.data file but with NNP energy and force predictions inserted.


  • Write out additional structure information file:

    nnp-predict 1