using Antique: V as potential is the technique to avoid conflicting variable names.
julia> V = [1 2; 3 4]
2×2 Matrix{Int64}:
1 2
3 4
julia> using Antique
WARNING: using Antique.V in module Main conflicts with an existing identifier.
julia> using Antique: V as potential
julia> HA = HydrogenAtom()
HydrogenAtom(1, 1.0, 1.0, 1.0, 1.0)
julia> V(HA,1)
ERROR: MethodError: objects of type Matrix{Int64} are not callable
Use square brackets [] for indexing an Array.
Stacktrace:
[1] top-level scope
@ REPL[5]:1
julia> potential(HA,1)
-1.0
using Antique: V as potentialis the technique to avoid conflicting variable names.