HessianMeasure

The HessianMeasure step calculates and records the Hessian matrix of the system, providing information about the curvature of the potential energy surface.

Output format:

#Id_i     Id_j     Hxx                 Hxy                 Hxz                 Hyx                 Hyy                 Hyz                 Hzx                 Hzy                 Hzz
1         1        1.2345678901e+00    2.3456789012e-01    3.4567890123e-02    2.3456789012e-01    4.5678901234e+00    5.6789012345e-01    3.4567890123e-02    5.6789012345e-01    6.7890123456e+00
1         2        -3.4567890123e-01   -4.5678901234e-02   -5.6789012345e-03   -4.5678901234e-02   -6.7890123456e-01   -7.8901234567e-02   -5.6789012345e-03   -7.8901234567e-02   -8.9012345678e-01
...

type: MechanicalMeasure, HessianMeasure
parameters:
- outputFilePath: string: Path to the output file
- mode: string: Calculation mode, either “Analytical” or “Numerical” (default: “Analytical”)
- outputPrecision: int: Number of decimal places in the output (default: 10)

Example:

"hessianMeasure":{
  "type":["MechanicalMeasure","HessianMeasure"],
  "parameters":{
    "intervalStep": 10000,
    "outputFilePath": "hessian_measure.dat",
    "mode": "Analytical",
    "outputPrecision": 12
  }
}

Note

The output file will contain the full Hessian matrix elements for each pair of particles.

Warning

The Hessian calculation can be computationally expensive, especially for large systems.

Tip

The Hessian matrix is useful for normal mode analysis and studying system stability.