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OpenMPCD
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Public Member Functions | |
| def | __init__ (self, prefactor, orientation) |
| def | getPrefactor (self) |
| def | getOrientation (self) |
| def | getPotential (self, r) |
Interactions between two constant and identical magnetic dipoles.
The general magnetic dipole-dipole interaction potential is given by
\f[
- \frac{ \mu_0 }{ 4 \pi r^3 }
\left(
3
\left(\vec{m_1} \cdot \hat{r} \right)
\left(\vec{m_2} \cdot \hat{r} \right)
-
\vec{m_1} \cdot \vec{m_2}
\right)
\f]
where \f$ \mu_0 \f$ is the vacuum permeability, \f$ \hat{r} \f$ and
\f$ r \f$ are, respectively, the unit vector and length of the vector
\f$ \vec{r} \f$ that points from one dipole's position to the other's,
\f$ \vec{m_1} \f$ and \f$ \vec{m_2} \f$ are the magnetic dipole moments, and
\f$ \cdot \f$ denotes the inner product.
In the special case treated in this class, the magnetic dipole moments are
assumed to be constant throughout time in size and orientation. Therefore,
with \f$ m \f$ being the magnitude of the individual dipole moments and with
\f$ \hat{m} \f$ being the unit vector of the individual dipole moments, the
interaction potential is given by
\f[
- \frac{ \mu_0 m^2 }{ 4 \pi r^3 }
\left( 3 \left(\hat{m} \cdot \hat{r} \right)^2 - 1 \right)
\f]
Definition at line 32 of file MagneticDipoleDipoleInteraction_ConstantIdenticalDipoles.py.
| def MPCDAnalysis.PairPotentials.MagneticDipoleDipoleInteraction_ConstantIdenticalDipoles.MagneticDipoleDipoleInteraction_ConstantIdenticalDipoles.__init__ | ( | self, | |
| prefactor, | |||
| orientation | |||
| ) |
The constructor.
@throw TypeError
Throws if `prefactor` is neither `int` nor `float`.
@throw TypeError
Throws if `orientation` is not an instance of `Vector3DReal`.
@throw ValueError
Throws if `prefactor` is negative.
@throw ValueError
Throws if `orientation` is not a unit vector.
@param[in] prefactor
The term \f$ \frac{\mu_0 m^2}{4 \pi} \f$, which must be
non-negative.
@param[in] orientation
The orientation unit vector \f$ \hat{m} \f$ of the dipole
moments.
Definition at line 54 of file MagneticDipoleDipoleInteraction_ConstantIdenticalDipoles.py.
| def MPCDAnalysis.PairPotentials.MagneticDipoleDipoleInteraction_ConstantIdenticalDipoles.MagneticDipoleDipoleInteraction_ConstantIdenticalDipoles.getOrientation | ( | self | ) |
Returns the orientation unit vector \f$ \hat{m} \f$ of the dipole
moments as an instance of `Vector3DReal`.
Definition at line 87 of file MagneticDipoleDipoleInteraction_ConstantIdenticalDipoles.py.
| def MPCDAnalysis.PairPotentials.MagneticDipoleDipoleInteraction_ConstantIdenticalDipoles.MagneticDipoleDipoleInteraction_ConstantIdenticalDipoles.getPotential | ( | self, | |
| r | |||
| ) |
Returns the potential for an input value of \f$ r \f$.
@throw TypeError
Throws if `r` is neither `int` nor `float` or `Vector3DReal`.
@throw ValueError
Throws if `r` is the zero vector.
@param[in] r
The input value, which must may be a non-zero vector of type
`Vector3DReal`.
Definition at line 105 of file MagneticDipoleDipoleInteraction_ConstantIdenticalDipoles.py.
| def MPCDAnalysis.PairPotentials.MagneticDipoleDipoleInteraction_ConstantIdenticalDipoles.MagneticDipoleDipoleInteraction_ConstantIdenticalDipoles.getPrefactor | ( | self | ) |
Returns the term \f$ \frac{\mu_0 m^2}{4 \pi} \f$ as a `float`.
Definition at line 77 of file MagneticDipoleDipoleInteraction_ConstantIdenticalDipoles.py.
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