user defined eos about clapeyron.jl HOT 2 OPEN

using Clapeyron
using Clapeyron: SecondVirialModel

struct MyParam <: EoSParam
    B::PairParam{Float64}
end

@newmodel ConstantBVirial SecondVirialModel MyParam false #the false is to opt out of SAFT association parameters

#if your model is a subtype of a second virial model, you only need to define the second virial coefficient.
function Clapeyron.second_virial_coefficient_impl(model::ConstantBVirial,T,z=SA[1.0])
    B = zero(T + eltype(z)) #adequate initial point
    Bij = model.params.B
    for i in @comps
      for j in @comps
        B += z[i]*z[j]*Bij[i,j]
      end
    end
    return B/sum(z)
end

julia> model = PCSAFT(["acetic acid"])
PCSAFT{BasicIdeal, Float64} with 1 component:
 "acetic acid"
Contains parameters: Mw, segment, sigma, epsilon, epsilon_assoc, bondvol

julia> saturation_temperature(model,1e5)
(391.61543076122626, 6.43973177383346e-5, 0.027157488839931063)

julia> model = PPCSAFT(["acetic acid"])
PPCSAFT{BasicIdeal} with 1 component:
 "acetic acid"
Contains parameters: Mw, segment, sigma, epsilon, dipole, dipole2, epsilon_assoc, bondvol

julia> saturation_temperature(model,1e5)
(389.7331841526761, 6.444345768928592e-5, 0.031801246734323926)

julia> model = PR(["acetic acid"])
PR{BasicIdeal, PRAlpha, NoTranslation, vdW1fRule} with 1 component:
 "acetic acid"
Contains parameters: a, b, Tc, Pc, Mw

julia> saturation_temperature(model,1e5)
(391.54160848876614, 8.25819698557481e-5, 0.0317628509893515)