Manganese 3x3 and sqrt3 x sqrt3-R30^o Structures and Structural Phase Transition on w-GaN(0001) Studied by
Scanning Tunneling Microscopy and First-principles Theory
Abhijit V. Chinchore,¹ Kangkang Wang,¹ Meng Shi,¹ Andrada Mandru,¹ Yinghao Liu,¹ Muhammad Haider,¹ Arthur R. Smith,¹ Valeria Ferrari,² Maria Andrea Barral,² and Pablo Ordejon<sup>3

1</sup>Nanoscale and Quantum Phenomena Institute, Physics and Astronomy, Ohio University, Athens, OH  45701, USA
²Centro Atómico Constituyentes, GIyA, CNEA, San Martín, Buenos Aires, Argentina
³Centre d'Investigació en Nanociència i Nanotecnologia - CIN2 (CSIC-ICN), Campus UAB, 08193 Bellaterra, Barcelona, Spain