Mr. Zuckerberg and his wife, Dr. Priscilla Chan, said they were forming a new organization, the Chan Zuckerberg Initiative, to manage the money, through an unusual limited liability corporate structure. [...] By using a limited liability company instead of a nonprofit corporation or foundation, the Zuckerberg family will be able to go beyond making philanthropic grants. They will invest in companies, lobby for legislation and seek to influence public policy debates, which nonprofits are restricted from doing under tax laws. A spokeswoman for the family said that any profits from the investments would be plowed back into the Chan Zuckerberg Initiative for future projects.