Add Hager-Zhang beta
Add Hager-Zhang beta

f-fathurrahman/ffr-ElectronicStructure.jl,f-fathurrahman/ffr-ElectronicStructure.jl,f-fathurrahman/ffr-ElectronicStructure.jl,f-fathurrahman/ffr-ElectronicStructure.jl,f-fathurrahman/ffr-ElectronicStructure.jl