qiskit-documentation/docs/api/qiskit/0.32/qiskit.chemistry.algorithms...

178 lines
5.4 KiB
Plaintext
Raw Permalink Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

---
title: PotentialBase
description: API reference for qiskit.chemistry.algorithms.pes_samplers.PotentialBase
in_page_toc_min_heading_level: 1
python_api_type: class
python_api_name: qiskit.chemistry.algorithms.pes_samplers.PotentialBase
---
# PotentialBase
<Class id="qiskit.chemistry.algorithms.pes_samplers.PotentialBase" isDedicatedPage={true} github="https://github.com/qiskit-community/qiskit-aqua/tree/stable/0.9/qiskit/chemistry/algorithms/pes_samplers/potentials/potential_base.py" signature="PotentialBase(molecule)" modifiers="class">
Bases: `qiskit.chemistry.algorithms.pes_samplers.potentials.potential_base.EnergySurfaceBase`, `qiskit.chemistry.algorithms.pes_samplers.potentials.potential_base.VibronicStructureBase`
Class to hold prescribed 1D potentials (e.g. Morse/Harmonic) over a degree of freedom.
## Methods
### dissociation\_energy
<Function id="qiskit.chemistry.algorithms.pes_samplers.PotentialBase.dissociation_energy" signature="PotentialBase.dissociation_energy(scaling=1.0)" modifiers="abstract">
Returns the dissociation energy (scaled by scaling)
**Return type**
`float`
</Function>
### eval
<Function id="qiskit.chemistry.algorithms.pes_samplers.PotentialBase.eval" signature="PotentialBase.eval(x)" modifiers="abstract">
After fitting the data to the fit function, predict the energy at a point x.
**Parameters**
**x** (`float`) value to evaluate surface in
**Return type**
`float`
**Returns**
value of surface in point x
</Function>
### fit
<Function id="qiskit.chemistry.algorithms.pes_samplers.PotentialBase.fit" signature="PotentialBase.fit(xdata, ydata, initial_vals=None, bounds_list=None)" modifiers="abstract">
Fits surface to data
**Parameters**
* **xdata** (`List`\[`float`]) x data to be fitted
* **ydata** (`List`\[`float`]) y data to be fitted
* **initial\_vals** (`Optional`\[`List`\[`float`]]) Initial values for fit parameters. None for default. Order of parameters is d\_e, alpha, r\_0 and m\_shift (see fit\_function implementation)
* **bounds\_list** (`Optional`\[`Tuple`\[`List`\[`float`], `List`\[`float`]]]) Bounds for the fit parameters. None for default. Order of parameters is d\_e, alpha, r\_0 and m\_shift (see fit\_function implementation)
**Return type**
`None`
</Function>
### get\_equilibrium\_geometry
<Function id="qiskit.chemistry.algorithms.pes_samplers.PotentialBase.get_equilibrium_geometry" signature="PotentialBase.get_equilibrium_geometry(scaling=1.0)" modifiers="abstract">
Get the equilibrium energy.
Returns the geometry for the minimal energy (scaled by scaling) Default units (scaling=1.0) are Angstroms. Scale by 1E-10 to get meters.
**Parameters**
**scaling** (`float`) scaling factor
**Return type**
`float`
**Returns**
equilibrium geometry
</Function>
### get\_maximum\_trusted\_level
<Function id="qiskit.chemistry.algorithms.pes_samplers.PotentialBase.get_maximum_trusted_level" signature="PotentialBase.get_maximum_trusted_level(n=0)">
Returns the maximum energy level for which the particular implementation still provides a good approximation of reality. Default value of 100. Redefined where needed (see e.g. Morse).
**Parameters**
**n** (`int`) vibronic mode
**Return type**
`float`
**Returns**
maximum\_trusted\_level setted
</Function>
### get\_minimal\_energy
<Function id="qiskit.chemistry.algorithms.pes_samplers.PotentialBase.get_minimal_energy" signature="PotentialBase.get_minimal_energy(scaling=1.0)" modifiers="abstract">
Get the minimal energy.
Returns the value of the minimal energy (scaled by scaling) Default units (scaling=1.0) are J/mol. Scale appropriately for Hartrees.
**Parameters**
**scaling** (`float`) scaling factor
**Return type**
`float`
**Returns**
minimum energy
</Function>
### get\_num\_modes
<Function id="qiskit.chemistry.algorithms.pes_samplers.PotentialBase.get_num_modes" signature="PotentialBase.get_num_modes()">
This (1D) potential represents a single vibrational mode
**Return type**
`int`
</Function>
### get\_trust\_region
<Function id="qiskit.chemistry.algorithms.pes_samplers.PotentialBase.get_trust_region" signature="PotentialBase.get_trust_region()">
The potential will usually be well-defined (even if not useful) for arbitrary x so we return a fairly large interval here. Redefine in derived classes if needed.
**Return type**
`Tuple`\[`float`, `float`]
</Function>
### update\_molecule
<Function id="qiskit.chemistry.algorithms.pes_samplers.PotentialBase.update_molecule" signature="PotentialBase.update_molecule(molecule)">
Wipe state if molecule changes, and check validity of molecule for potential.
**Parameters**
**molecule** (`Molecule`) chemistry molecule
**Return type**
`Molecule`
**Returns**
molecule used
</Function>
### vibrational\_energy\_level
<Function id="qiskit.chemistry.algorithms.pes_samplers.PotentialBase.vibrational_energy_level" signature="PotentialBase.vibrational_energy_level(n)" modifiers="abstract">
Returns the n-th vibrational energy level for a given mode.
**Parameters**
**n** (`int`) number of vibrational mode
**Return type**
`float`
**Returns**
n-th vibrational energy level for a given mode
</Function>
</Class>