All atoms of one kind share common properties. It means when people work together and for the common good.basically the unity means the totality or combining all its parts in to one.for example. @soraphis Ok, I was thinking last days about what you wrote. I agree with you (but not at all). Now I register and handle things in one script, it's quite useful, thank you:) But on the other hand, sometimes I just want to use a Listener, because I don't want to code a register logic in some script, but only a method which could be called through Listener component.
Atomic units (au or a.u.) form a system of natural units which is especially convenient for atomic physics calculations. Atomic units, like SI units, have a unit of mass, a unit of length, and so on. However, the use and notation is somewhat different from SI. Suppose a particle with a mass of m has 3.4 times the mass of electron. The value of mass (m) can be written in three ways:
- (m=3.4; m_e): This is the clearest notation (but least common), where the atomic unit is included explicitly as a symbol.
- (m=3.4; a.u.): This notation is ambiguous, but is common. Here, it means that the mass m is 3.4 times the atomic unit of mass. If considering a length L of 3.4 times the atomic unit of length, the equation would look the same, (L= 3.4 ;a.u.) The dimension needs to be inferred from context, which is sloppy.
- (m = 3.4): This notation is similar to the previous one, and has the same dimensional ambiguity. It comes from formally setting the atomic units to 1 (Table (PageIndex{1})).
This article deals with 'Hartree type' of atomic units, where the numerical values of the following four fundamental physical constants are all unity by definition:
| Dimension | Name | Symbol/Definition | Value in SI units | Value in Atomic Units |
|---|---|---|---|---|
| mass | electron rest mass | (m_e) | 9.109×10−31 kg | 1 |
| charge | elementary charge | (e) | 1.602×10−19 C | 1 |
| action | reduced Planck's constant | (hbar = dfrac{h}{2pi}) | 1.054×10−34 J·s | 1 |
| electric constant−1 | Coulomb force constant | (displaystyle k_e = frac{1}{4 pi epsilon_o}) | 8.987 x 109 kg·m3·s−2·C−2 | 1 |
Use the atomic units definitions in Table (PageIndex{1}) to contrast the Hamiltonian for a Helium atom in Si units and in atomic units.
Solution
In SI units, the Hamiltonian for a Helium atom is
[ hat {H} = -dfrac {hbar ^2}{2m_e} (nabla ^2_1 + nabla ^2_2) -dfrac {2e^2}{4 pi epsilon _0 r_1} - dfrac {2e^2}{4 pi epsilon _0 r_2} + dfrac {e^2}{4 pi epsilon _0 r_{12}} nonumber]
In atomic units, the same Hamiltonian
[ hat {H} = -dfrac {1}{2} (nabla ^2_1 + nabla ^2_2) - dfrac {2}{r_1} - dfrac {2}{r_2} + dfrac {1}{r_{12}} nonumber]
All the units that make the SI version of the Hamiltonian disappear to emphasize the key aspects of the operator.
Atomic units are derived from certain fundamental properties of the physical world, and are free of anthropocentric considerations. It should be kept in mind that atomic unites were designed for atomic-scale calculations in the present-day universe, with units normalize the reduced Planck constant and also mass and charge of the electron are set to 1, and, as a result, the speed of light in atomic units is a large value, (1/alpha approx 137). For example, the orbital velocity of an electron around a small atom is of the order of 1 in atomic units. Table (PageIndex{2}) give a few derived units. Some of them have proper names and symbols assigned, as indicated in the table.
| Dimension | Name | Symbol | Expression | Value in SI units | Value in more common units |
|---|---|---|---|---|---|
| length | bohr | (a_o) | (4pi epsilon_0 hbar^2 / (m_mathrm{e} e^2) = hbar / (m_mathrm{e} c alpha) ) | 5.291×10−11 m | 0.052 nm = 0.529 Å |
| energy | hartree | (E_h) | (m_mathrm{e} e^4/(4piepsilon_0hbar)^2 = alpha^2 m_mathrm{e} c^2 ) | 4.359×10−18 J | 27.2 eV = 627.5 kcal·mol−1 |
| time | (hbar / E_mathrm{h}) | 2.418×10−17 s | |||
| velocity | ( a_0 E_mathrm{h} / hbar = alpha c) | 2.187×106 m·s−1 |
This chapter outlines the theoretical concepts behind Unity Atoms. This knowledge helps you better understand a new way of thinking about data and state in your project.
Fundamentals
Unity Atoms is an event based system that encourages the game to be ass called on OnEnable as well as before setting a new Value of a Variable. An example of a pre change transformer is ClampInt, an IntIntFunction that clamps the Variable's value between two values.
Your pre change transformers can contain as much or as little logic as necessary for your project and you can chain them in the Inspector.
Constants
Constants behave exactly the same as Variables, but can not be changed via script and therefore do not contain the change Events that Variables do.
References
Unity Atmosphere
References are values that can be toggled between Use Value, Use Constant, Use Variable or Use Variable Instancer via the Unity Inspector.
When a Reference is set to Use Value it functions exactly like a regular serialized variable in a MonoBehaviour script. However, when it is set to Use Variable or Use Constant it uses a Variable or a Constant. When it's set to Use Variable Instancer you can drag and drop a Variable Instancer of the correct type.
Variable Instancers
This is a MonoBehaviour that takes a base Variable and makes an in memory copy of it OnEnable. This is particular useful when working with prefabs that are going to be instantiated at runtime. You can also give the Variable Instancer a reference to a List or a Collection. If you do that the Variable Instancer will add the in memory Variable on Start to the List or Collection and then later remove it on OnDestroy.
Pairs
Pairs are simple structs containing two variables of the same type, used for example in Variables' Changed With History Event.
Events
Events
An Event is a thing that happens in the game that Listeners can listen for. Events in Unity Atoms are also Scriptable Objects that live outside of a specific scene. It is possible to raise an Event from the Unity Inspector for debugging purposes.
Pair Events
Like Event, but for pairs.
Event References
Event References are Events that can be toggled between Use Event, Use Event Instancer, Use Variable or Use Variable Instancer via the Unity Inspector. When an Event Reference is set to Use Event it functions exactly like a regular serialized Event in a MonoBehaviour script. When it is set to Use Event Instancer you can drag and drop an Event Instancer whose Event the Event Reference will use. When it is set to Use Variable it is going to use the Event associated with the Variable's Changed Event. When it's set to Use Variable Instancer you can drag and drop a Variable Instancer of the correct type and it will use its associated Changed Event.
Event Instancers
Unity Particles Script
This is a MonoBehaviour that takes a base Event and makes an in memory copy of it on OnEnable. This is particularly useful when working with prefabs that are going to be instantiated at runtime, for example when working with Mono Hooks on your prefabs.
Pair Event Instancers
Like Event Instancer, but for pairs.
Unity Atom Streamer
Listeners
Event Reference Listeners
A Listener listens to an Event reference and raises zero to many responses to that Event Reference. Listeners are MonoBehaviours that live in a scene. See below for more information on the type of responses that is supported.
Pair Event Reference Listeners
Like Event Reference Listeners, but for pairs.
Responses
Responses are raised by a Listener in response to an Event. Responses can live both in the scene as UnityEvents or outside the scene as a Scriptable Object in the shape of an Action.
Unity Particles Youtube
Actions
An Action in Unity Atoms is a C# function as a Scriptable Object. An Action can be used as a response in a Listener. Since Scriptable Objects can be created as assets in the project, Actions are well suited for responses that may have different default values.
Pair Actions
Like Actions, but for pairs.
Functions
A Function in Unity Atoms is basically the same as an Action, but while an Actions does not return something a Function does.
Collections
Collections store multiple values. For all collections in Unity Atoms there is the possibility to add Events for the following:
- An item is added.
- An item is removed.
- The collection is cleared.
Value Lists
A Value List is an array of values that is stored as a Scriptable Object.
Lists
A List is an array of Variables that is stored as a Scriptable Object. The Variables stored in a List can be of different types.
Collections
A collection is a set of Variables associated with a StringReference key and is stored as a Scriptable Object. The Variables stored in a Collection can be of different types.