Recently I read in a news post that the Treasury Department is able to order the coinage of a coin made of platinum with a value of 1,000,000,000,000 USD, or 1 trillion US dollars.
You can read about this subject The Trillion Dollar Coin Idea To Save The Economy(courtesy of Business Insider):

The premise of the idea is this: Although the Treasury can't just
create money out of thin air to pay its bills, there is a technicality
in the law that says the Treasury has special discretion to create
platinum coins of any denomination, and the thinking is that Tim
Geithner could make the coin and walk it over to the Federal Reserve
and deposit it in the Treasury's bank account.

The opinion of the winner of the Economics prize in memory of Alfred Nobel Paul Krugman (Conscience of a Liberal, The Opinion Pages):

First, as a legal matter the Federal government can’t just print money
to pay its bills, with one peculiar exception. Instead, money has to
be created by the Federal Reserve, which then puts it into circulation
by buying Federal debt. You may say that this is an artificial
distinction, because the Fed is effectively part of the government;
but legally, the distinction matters, and the debt bought by the Fed
counts against the debt ceiling.

The peculiar exception is that clause allowing the Treasury to mint
platinum coins in any denomination it chooses. Of course this was
intended as a way to issue commemorative coins and stuff, not as a
fiscal measure; but at least as I understand it, the letter of the law
would allow Treasury to stamp out a platinum coin, say it’s worth a
trillion dollars, and deposit it at the Fed — thereby avoiding the
need to issue debt.

My questions are:

  • Is this legal? If I am not wrong, only the Fed has the power to print official money?
  • Who will accept this coin, and how will this coin save the economy?