At least two answers to your question: 1) He authored http://en.wikipedia.org/wiki/Li%27s_criterion http://en.wikipedia.org/wiki/Li%27s_criterion 2) I believe

At least two answers to your question: 1) He authored http://en.wikipedia.org/wiki/Li%27s_criterion http://en.wikipedia.org/wiki/Li%27s_criterion 2) I believe some theorists have already looked at it and I haven't heard anything negative [disclaimer: I'm far from an expert and wouldn't be able to even agree or disagree with their analyses].