A two-month-old startup from the former head of artificial intelligence at Databricks Inc. has raised a seed round of funding from investors at a valuation of $4.5 billion for its effort to build a novel, more energy-efficient computer for AI.Unconventional AI raised $475 million in a deal co-led by Andreessen Horowitz and Lightspeed Venture Partners, said Naveen Rao, who left Databricks in September and is chief executive officer of the startup. Other investors include Lux Capital and DCVC. Dat...