.. index:: pair: class; rgpot::MorsePot
.. _doxid-classrgpot_1_1_morse_pot:

class rgpot::MorsePot
=====================

.. toctree::
	:hidden:

Overview
~~~~~~~~

Pairwise Morse potential, :math:`V(r) = D_e [1 - e^{-a(r - r_e)}]^2 -
D_e`, shifted so that :math:`V(r_\mathrm{cut}) = 0`. :ref:`More...<details-classrgpot_1_1_morse_pot>`


.. ref-code-block:: cpp
	:class: doxyrest-overview-code-block

	#include <MorsePot.hpp>
	
	class MorsePot: public rgpot::Potential< MorsePot > {
	public:
		// construction
	
		:target:`MorsePot<doxid-classrgpot_1_1_morse_pot_1a8201d329380897297a5093baf3c19755>`();
		:target:`MorsePot<doxid-classrgpot_1_1_morse_pot_1addc06a3d73a91c1d525471f098966415>`(const :ref:`MorseConfig<doxid-structrgpot_1_1_morse_config>`& c);

		// methods
	
		const :ref:`MorseConfig<doxid-structrgpot_1_1_morse_config>`& :target:`config<doxid-classrgpot_1_1_morse_pot_1ad57a07db670a719fa44b94fe220d0881>`() const;
		double :ref:`energyShift<doxid-classrgpot_1_1_morse_pot_1a4a12503dd2fb3c2ac2efbc86a3ae27c7>`() const;
		virtual uint64_t :ref:`paramsKey<doxid-classrgpot_1_1_morse_pot_1a3efdba266543f10b6b5c18ad0384e4ce>`() const;
		void :ref:`forceImpl<doxid-classrgpot_1_1_morse_pot_1ad87ad7cbb6c64258f8471c594424e6c9>`(const :ref:`ForceInput<doxid-structrgpot_1_1_force_input>`& in, :ref:`ForceOut<doxid-structrgpot_1_1_force_out>`* out) const;
	};
.. _details-classrgpot_1_1_morse_pot:

Detailed Documentation
~~~~~~~~~~~~~~~~~~~~~~

Pairwise Morse potential, :math:`V(r) = D_e [1 - e^{-a(r - r_e)}]^2 -
D_e`, shifted so that :math:`V(r_\mathrm{cut}) = 0`.

Pairwise interactions within the cutoff radius, minimum image convention on an orthogonal box. Pairs come from the shared ``:ref:`rgpot::nlist::PairListCache <doxid-classrgpot_1_1nlist_1_1_pair_list_cache>```, so repeated evaluations on nearby geometries (NEB images, dimer rotations) reuse a Verlet-skin cached candidate list.

.. warning::

	The box is assumed to be orthogonal.

Methods
-------

.. index:: pair: function; energyShift
.. _doxid-classrgpot_1_1_morse_pot_1a4a12503dd2fb3c2ac2efbc86a3ae27c7:

.. ref-code-block:: cpp
	:class: doxyrest-title-code-block

	double energyShift() const

Energy offset subtracted from every pair term (the unshifted well depth at the cutoff).

.. index:: pair: function; paramsKey
.. _doxid-classrgpot_1_1_morse_pot_1a3efdba266543f10b6b5c18ad0384e4ce:

.. ref-code-block:: cpp
	:class: doxyrest-title-code-block

	virtual uint64_t paramsKey() const

Fingerprint of the potential's parameter set.

Mixed into the result-cache key so results never cross parameter sets. Implementations hash their config field by field (see :ref:`ParamHash.hpp <doxid-_param_hash_8hpp_source>`) plus a kernel-version salt that changes whenever the numerics change. The default (0) suits parameter-free potentials whose numerics never changed.

.. index:: pair: function; forceImpl
.. _doxid-classrgpot_1_1_morse_pot_1ad87ad7cbb6c64258f8471c594424e6c9:

.. ref-code-block:: cpp
	:class: doxyrest-title-code-block

	void forceImpl(const :ref:`ForceInput<doxid-structrgpot_1_1_force_input>`& in, :ref:`ForceOut<doxid-structrgpot_1_1_force_out>`* out) const

Computes the forces and energy for a given configuration.



.. rubric:: Parameters:

.. list-table::
	:widths: 20 80

	*
		- in

		- Structure containing coordinates and cell info.

	*
		- out

		- Pointer to the results structure.



.. rubric:: Returns:

Void.