Update Basis.jl, Close #11

Author: ohno

src/Basis.jl

@@ -113,6 +113,8 @@ BS = BasisSet(
 """ BasisSet
 
 @doc raw"""
+`geometric(r₁, rₙ, n::Int; nₘₐₓ::Int=n, nₘᵢₙ::Int=1)`
+
 Exponents of Gaussian basis functions are given by geometric progression:
 ```math
 \begin{aligned}
@@ -156,7 +158,15 @@ julia> ν = TwoBody.geometric(0.1, 10.0, 5, nₘₐₓ = 10)
 @doc raw"""
 `GeometricBasisSet(basistype, r₁, rₙ, n; nₘᵢₙ=1, nₘₐₓ=n)`
 
-This is a basis set with exponentials generated by `geometric()`.
+This is a basis set with exponentials generated by `geometric(r₁, rₙ, n; nₘₐₓ=n, nₘᵢₙ=1)`. You can define the same basis set as Table A2 in [E. Hiyama, M. Kamimura, Front. Phys. 13, 132106 (2018)](https://doi.org/10.1007/s11467-018-0828-5) like this:
+```math
+  r_1 = 0.1,
+  r_{n_\mathrm{max}} = 80.0,
+  n_\mathrm{max} = 20.
+```
+```@example
+BS = GeometricBasisSet(SimpleGaussianBasis, 0.1, 80.0, 20)
+```
 """ GeometricBasisSet
 
 @doc raw"""