OpenAI plans to invest roughly $400 billion to develop five new US data center sites in partnership with Oracle Corp. and SoftBank Group Corp., marking the biggest push yet to fulfill an earlier pledge to spend a half-trillion dollars on artificial intelligence infrastructure in the country.The new locations, spread across Texas, New Mexico and Ohio, will eventually have a capacity of 7 gigawatts of power, or as much as some cities, the companies said Tuesday. The plans were announced by executi