It is not an accurate description of their views, but nonetheless it's also incorrect to call them "white nationalists".

I was watching a live stream (with chat) when this act of murderous terrorism was perpetrated.  The chat exploded with "Sieg Heils", "Heil Hitlers" and "14/88s" (look that one up if you must).  

Call it what it is:  white racism.

Call them what they are:  "American" Nazis.