AtomicLevels

AtomicLevels provides a collections of types and methods to facilitate working with atomic states (or, more generally, states with spherical symmetry), both in the relativistic (eigenstates of J = L + S) and non-relativistic (eigenstates of L and S separately) frameworks.

• Orbitals and orbital subshells
• Configurations
• Configuration state functions (CSFs)
• Term symbols

The aim is to make sure that the types used to label and store information about atomic states are both efficient and user-friendly at the same time. In addition, it also provides various utility methods, such as generation of a list CSFs corresponding to a given configuration, serialization of orbitals and configurations, methods for introspecting physical quantities etc.

To install and load the package, you can just type in the Julia REPL

julia> using Pkg; Pkg.add("DataFrames")
julia> using AtomicLevels

As a simple usage example, constructing a configuration for an S-like state with an open 3p shell looks like

julia> configuration = c"[Ne]* 3s2 3p4"
1s² 2s² 2p⁶ 3s² 3p⁴

which is of type Configuration. To access information about subshells, you can index into the configuration which returns a tuple. The tuple contains an Orbital object, so you can, for example, ask for the ℓ and s angular momentum quantum numbers of the subshell

julia> shell = configuration[end]
(3p, 4, :open)

julia> angular_momenta(shell[1])
(1, 1/2)

Also, you can convert the configurations to the corresponding relativistic configurations and CSFs by simply doing

julia> rconfigurations = relconfigurations(configuration)
3-element Array{Configuration{RelativisticOrbital{Int64}},1}:
 1s² 2s² 2p-² 2p⁴ 3s² 3p-² 3p²
 1s² 2s² 2p-² 2p⁴ 3s² 3p- 3p³
 1s² 2s² 2p-² 2p⁴ 3s² 3p⁴

julia> csfs(rconfigurations)
5-element Array{CSF{RelativisticOrbital{Int64},HalfIntegers.Half{Int64},Seniority},1}:
 1s²(₀0|0) 2s²(₀0|0) 2p-²(₀0|0) 2p⁴(₀0|0) 3s²(₀0|0) 3p-²(₀0|0) 3p²(₀0|0)+
 1s²(₀0|0) 2s²(₀0|0) 2p-²(₀0|0) 2p⁴(₀0|0) 3s²(₀0|0) 3p-²(₀0|0) 3p²(₂2|2)+
 1s²(₀0|0) 2s²(₀0|0) 2p-²(₀0|0) 2p⁴(₀0|0) 3s²(₀0|0) 3p-(₁1/2|1/2) 3p³(₁3/2|1)+
 1s²(₀0|0) 2s²(₀0|0) 2p-²(₀0|0) 2p⁴(₀0|0) 3s²(₀0|0) 3p-(₁1/2|1/2) 3p³(₁3/2|2)+
 1s²(₀0|0) 2s²(₀0|0) 2p-²(₀0|0) 2p⁴(₀0|0) 3s²(₀0|0) 3p⁴(₀0|0)+

For more examples and information about how to work with the various types, please see the documentation.