Among \(\mathrm{V}{\left(\mathrm{CO}\right)}_{6},\mathrm{Cr}{\left(\mathrm{CO}\right)}_{5},\mathrm{Cu}{\left(\mathrm{CO}…

Among \(\mathrm{V}{\left(\mathrm{CO}\right)}_{6},\mathrm{Cr}{\left(\mathrm{CO}\right)}_{5},\mathrm{Cu}{\left(\mathrm{CO}\right)}_{3},\mathrm{Mn}{\left(\mathrm{CO}\right)}_{5},\mathrm{Fe}{\left(\mathrm{CO}\right)}_{5},{\left[\mathrm{Co}{\left(\mathrm{CO}\right)}_{3}\right]}^{3-},{\left[\mathrm{Cr}{\left(\mathrm{CO}\right)}_{4}\right]}^{4-}\),and \(Ir(\mathrm{CO}{)}_{3}\), the total number of species isoelectronic with \(\mathrm{Ni}(\mathrm{CO}{)}_{4}\) is _______
[Given, atomic number: \(V=23,Cr=24,Mn=25,Fe=26,Co=27,Ni=28,Cu=29,Ir=77\) ]