I`m not sure if HyperChem supports pseudopotentials, but for the correct description of Pb complex you should use:

for ligand-6-311G(d,p) basis set at least;

for Pb some pseudoV for example MWB78;

I`m not sure if HyperChem supports pseudopotentials, but for the correct description of Pb complex you should use:

for ligand-6-311G(d,p) basis set at least;

for Pb some pseudoV for example MWB78;

Personally I do not recommend you to use HyperChem for these purposes. May be now it's better it used to be when I tried it, but it seem me to be impractically slow. As for me the better solution would be to use Firefly, ORCA, GAMESS or Priroda. All of them are free, have quite diverse basis sets so you can find basis sets that suit your need. For example all basis sets in Priroda have ECP or basis functions for Pb. You do not need to make something special. The only problem is to get Priroda. If you are interested I can write you directly how.

I am interested in this programme but not is if it's free or it is necessary to pay any fee.How could get priroda?

I also do not recommend use for HyperChem because of less accuracy, no different functions(variation of basis sets and methods) and slow the programs. You can use Gaussian, Gamess because there are lot of calculation methods and different basis sets.

About Priroda. It's absolutely free. You should write to it's author Dimitry Laikov dimitri_laikov [at] mail.ru. He'll provide you a link.

The drawback of it (as in all other aforementioned programs) is it has no graphical user interface - it's purely command line. Usually quantum chemists are not care about it. But for newbie quantum chemist (sorry I don't know you experience in the field) it can be hard for the first time. However you can google - there is some programs that can read Priroda files (e.g. or file can be converted into form that can be readable by many GUI programs like HiperChem.

Firefly or GAMESS can also be good solution for you. However for transition elements you'll have to look for basis sets and implement them.

Thank soo much for all this.

If you have access to Gaussian or Turbomol use them, if not use free ORCA, GAMESS, etc. Again, look up at the available basis sets on https://bse.pnl.gov/bse/portal if you do localized orbital calculations.

If you have periodic systems (crystals) then better use VASP, Wien2K etc.

Do not forget to perform relativistic correction (spin-orbit coupling), because Pb is heavy element.

Thanks for your advice!

Hyperchem is not use full to run a molecule has Pb atom. However you can use hyperchem to generate initial structure and then take the structure coordinates and reoptimized it using Gaussian 09 where psudo potential like LANL2TZ basis set for Pb whereas the other atoms, use Pople basis sets such as 6-311+G*