Charge number oxidation number of a monatomic ion. For example, the oxidation number of <chem>Li+</chem> is +1. This helps when trying to solve oxidation questions. A charge number also can help when drawing Lewis dot structures. For example, if the structure is an ion, the charge will be included outside of the Lewis dot structure. Since there is a negative charge on the outside of the Lewis dot structure, one electron needs to be added to the structure. If the charge was positive, an electron would be lost and taken away. For an atomic nucleus, which can be regarded as an ion
Drude particle a changing local environment. Classical Drude particles are massless virtual sites carrying a partial electric charge, attached to individual atoms via a harmonic spring. The spring constant and relative partial charges on the atom and associated Drude particle determine its response to the local electrostatic field, serving as a proxy for the changing distribution of the electronic charge of the atom or molecule. However, this response is limited to a changing dipole moment. This response is not enough to model interactions in environments with large field gradients, which interact with higher order moments. The major computational cost of simulating classical