DLVO ---- The DLVO (Derjaguin-Landau-Verwey-Overbeek) potential combines electrostatic repulsion with van der Waals attraction to model colloidal interactions in aqueous solutions. It is the sum of a repulsive electrostatic term (Debye-Hückel) and an attractive van der Waals term (typically modeled as a Lennard-Jones potential). .. math:: U_{DLVO} = U_{DH} + U_{LJ} where: * :math:`U_{DH}` is the Debye-Hückel potential * :math:`U_{LJ}` is the Lennard-Jones potential The Debye-Hückel term is given by: .. math:: U_{DH} = \frac{q_i q_j}{4\pi\epsilon_0\epsilon_r} \frac{e^{-r/\lambda_D}}{r} The Lennard-Jones term can be any of the three types (Type1, Type2, or Type3) as described in the LennardJones potential documentation. ---- * **type**: ``NonBonded``, ``DLVOType1`` (or ``DLVOType2`` or ``DLVOType3``) * **parameters**: * ``cutOffNPFactor``: ``real``: Interaction range for LJ as a multiple of sigma * ``cutOffDHFactor``: ``real``: Interaction range for DH as a multiple of the Debye length * ``dielectricConstant``: ``real``: Relative permittivity of the medium :math:`\epsilon_r` * ``debyeLength``: ``real``: Debye length :math:`\lambda_D` :math:`[distance]` * **data**: * ``name_i``: ``string``: Type of particle i * ``name_j``: ``string``: Type of particle j * ``epsilon``: ``real``: LJ potential well depth :math:`[energy]` * ``sigma``: ``real``: LJ zero-potential distance :math:`[distance]` Example: .. code-block:: "dlvo":{ "type":["NonBonded","DLVOType1"], "parameters":{ "cutOffNPFactor":2.5, "cutOffDHFactor":3.0, "dielectricConstant":78.5, "debyeLength":1.0, "condition":"all" }, "labels":["name_i", "name_j", "epsilon", "sigma"], "data":[ ["A", "A", 1.0, 1.0], ["A", "B", 1.2, 0.9], ["B", "B", 0.8, 1.1] ] } .. note:: The DLVO potential uses the charge and radius information stored in the particle data. Ensure that these properties are properly set for each particle before using this potential. .. warning:: The DLVO theory has limitations and may not accurately describe all colloidal systems, especially at short distances or in highly concentrated solutions.