1. Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, 20899, MD, USA
2. Theiss Research, La Jolla, 92037, CA, USA
3. Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, 20899, MD, USA
4. Department of Computer Science, Aberystwyth University, SY23 3DB, UK
5. Scientific Computing Department, Rutherford Appleton Laboratory, Science and Technology Facilities Council, Harwell Campus, Didcot, OX11 0QX, UK