Tomography experiments are done at the magnification of 42000X (pixel size = 2.1 Å 2 /pixel) with an electron dose rate of 5 e -/A 2 per tilt image, 120 tilt images range from -60 to +60 degrees, with an accumulated dose ~600 e -/A 2 . The target defocus of the tilt series is 3 μm. HRTEM experiments are done at the magnification of 215000X (pixel size = 0.412 Å 2 /pixel) with an electron dose of 45 e -/A 2 per image. The target defocus is Scherzer defocus in order to obtain high resolution phase contrast. This was achieved by adjusting the defocus value based on a series of short exposures before the final image. Electron diffraction data were collected with a nominal camera length of 680 mm.