Sort spin-orbitals by spatial orbitals, then by projections

JuliaAtoms · Dec 19, 2023 · f8b4de1 · f8b4de1
1 parent b3ef25a
commit f8b4de1
Showing 1 changed file with 12 additions and 3 deletions.
diff --git a/src/spin_orbitals.jl b/src/spin_orbitals.jl
@@ -71,9 +71,6 @@ end
 
 degeneracy(::SpinOrbital) = 1
 
-# We cannot order spin-orbitals of differing orbital types
-Base.isless(a::SpinOrbital{O,M}, b::SpinOrbital{O,N}) where {O<:AbstractOrbital,M,N} = false
-
 function Base.isless(a::SpinOrbital{<:O,M}, b::SpinOrbital{<:O,M}) where {O,M}
     a.orb < b.orb && return true
     a.orb > b.orb && return false
@@ -86,6 +83,18 @@ function Base.isless(a::SpinOrbital{<:O,M}, b::SpinOrbital{<:O,M}) where {O,M}
     return false
 end
 
+function Base.isless(a::SpinOrbital{O,M}, b::SpinOrbital{O,M}) where {O,M}
+    a.orb < b.orb && return true
+    a.orb > b.orb && return false
+
+    for (ma,mb) in zip(a.m,b.m)
+        ma < mb && return true
+        ma > mb && return false
+    end
+    # All projections were equal
+    return false
+end
+
 function Base.isless(a::SpinOrbital{<:Orbital}, b::SpinOrbital{<:Orbital})
     a.orb < b.orb && return true
     a.orb > b.orb && return false